Very definitely a problem. I believe there has been a few other reports of this same problem on late model Hondas.

I would not have it driven in, but have it towed/hauled in to the garage. Something is stuck, or a glitch occurred in the electronincs.

At 45 mph, I'm surprised there was not enough braking effort available to bring the vehicle to a stop (assuming its an automatic). There is something fishy here. If the throttle was stuck open, a driver should be able to overpower it with extra effort. If the engine was shut down while under way and vacuum boost lost (by pumping), the brakes should still work, but would require much more effort.

If the brake pedal went all the way to the floor without supplying enough braking, there is something wrong with brakes. If the ABS system kicks in, a brake pedal can sink part way down and may give the impression that it "went to the floor" when in fact, it only sank part way. The first time this happens to an unsuspecting driver, it gives one a "sinking" feeling.

as jemdandy says don't even think of driving it anywhere.Have it towed. And where you are taking it it had better be your dealership not the goof off down the street that you think you can afford because the dealer is a rip off. the dealer can pull the scan and real live data on what actualy happened at the exact time. they can even tell you when you changed your radio station,what station you changed to and at what time.