There are so many crack installers around, I could just imagine how that thing was built. I would bet there is no preslope and the weepholes were not done correctly. The water is probably just laying there pooled up because it cannot naturally drain out, and your paper towel is wicking it out.

"The problem I have is that the kind of person who couldn't get a good install to a clean subfloor is not the kind of person who is likely to spend the time necessary to get the Durock clean enough to reuse." That was the point of my first post. An installer who buggers up an installation with pristine materials in a new installation will probably suffer more pain when trying to rebuild over once-used surfaces. "The new installers do not want to use the existing Durock." That is a very good sign. They want ownership and control of their work from start-to-finish. Have a good talk with them. They already know what happened with the first installation. But tell them your expectations. Tell them how the last installer failed to meet your expectations. Things to think about, and to possibly discuss with the installers: The tile pattern. Where center lines or grout lines will fall on the floor. Example, will a full tile be centered on the centerline of the floor, or a grout line? Discuss grout line width and what you expect for consistency throughout the floor. Discuss lippage between adjacent tiles. That Crossville tile has a pretty subtle pattern, but if you care how the veining in the tile flows, discuss it. Some people like the veining to flow in the same direction. Some prefer random. Again, you have a small floor and a subtle pattern...but it's worth thinking about. Some tile styles have a set number of patterns within that style, ie, there might be 14 different patterns in that style of tile. If they find repetition, let them know to not put two similar tiles next to one another in the same orientation.I'm not sure if your tile has repetition And again, with a small floor, it's not normally an issue. Many of the things I brought up might not apply to your installation. But discussions held before any thinset is mixed can eliminate frustrations down the road. They also show the installer that you're an interested party, and that you'll appreciate the effort they put towards giving you a quality installation. I'm not sure which finish you have on that tile, but there are grout release and sealing restrictions with the satin finish. You can find all that on the manufacturers website. Again, good luck!

Big edit for this post, you posted the Kerdi shot while I was typing. So... 1) The flex in the floor that is causing the grout to crack: It's possible that the Kerdi Tray was not properly bedded in thinset, so as the slightly flexible tray flexes, the inflexible grout is cracking. It's also possible that the small size of the penny rounds is resulting in point loading on the foam tray. The foam compresses ever-so-slightly, the tile moves, the grout cracks. The floor...Is your guy using thinset as grout? Grout as thinset? With the penny rounds, it almost looks like he's doing an all-at-once installation. Setting the tile, promoting between-the-tile-squeeze-through, then grouting. All at the same time. A negative with that is that he's grouting and cleaning the grout before the thinset has fully cured. When I grout I'm pretty aggressive with the grout float in order to get grout into every nook and cranny. I don't want to leave any voids. If your guy took it easy when grouting so as to not displace the unbonded sheets of penny rounds, he could have left a few voids beneath the surface. If he wanted to be gentle while cleaning the grout, he might have used too much water during cleanup, that can also weaken the grout. I don't know why the floor is being grouted piecemeal. That's an easy way to get uneven grout color on a floor. As he continues to tile, he'll have to chip out parts of the hardened thinset/grout at the edges fo the already installed sheets to get the subsequent sheets of tile to mesh with the already installed sheets. He'll need to be careful to not ding the Kerdi membrane. It's also a recipe for mismatched spacing at the edges resulting in being able to see the individual sheets of tile versus the floor being one harmonious surface of penny rounds. With him sliding the floor tile under the bottom course of wall tile, I do hope he's not leaving any unfilled voids in the floor-wall corners. 2) Bullnosing. He bullnosed the tile after they were on the wall? Yeah. Probably not going to get a good outcome. Should be an easy remove and replace. The bowed wall? The tiler tiles on what he gets. If he gets a bowed wall courtesy of the framers, he can put the blinders on and tile right over it...or he can address the bowed walls with whoever hired him...the GC? The homeowner? Then the tiler can either tile right over the bowed wall, OR he can have the contractor fix the wall before he tiles, OR he can repair the wall himself and then tile. One added item...I can't tell what exactly is going on int he bottom left corner of the already installed tile. Could simply be that the tile spacing is skewed and he lost the pattern. After this floor is done and everything cured, I'd recommend having the GC pull the drain grate, install a plug, and flood the floor. As the floor tile is covered with water, watch for air bubbles. They'll indicate voids under the tile or in the corners. Once flooded, pull the plug to see how the floor drains. Make sure it drains completely and that water is not held in the corners. With a Kerdi Tray, the slope of the floor and a properly draining floor should be a no-brainer. But based on what I'm seeing and what you described regarding the bullnose, this could be a "no brain" installation. Sorry for that. Remediation after-the-fact is always a tough spot to be in. Good luck.

Installing mosaic tiles isn't easy. Even though they come in 12"x12" sheets (most of the time) it isn't easy to do a perfect job. Not easy doesn't mean not doable. Like Chispa said, what he said is that he doesn't time/patience for it in other words. He has to make sure that the foundation that he puts on the mosaic is as flat as possible for him to install properly, level the sheets (mosaics) and need to tape after the install to make sure the tiles settle properly. With that being said, he can definitely install the mosaic a lot better but removing the sheets and reinstalling means more time and more material. You have to make this decision as no one but you will see this everyday.