I know its illegal, and I don't dump my tanks in such an manner.
I had only heard stories, and its a little odd to have the dump valve under the bus on the passenger side, with a remote switch next to the driver.
Remember a couple of years ago in Chicago??? The Dave Matthews Band bus had just such a switch. Seems the driver hit the aforementioned switch while crossing one of the Chicago River bridges. Wouldn't have made the news except for the sightseeing tour boat that had the unfortunate timing to be crossing under the bridge at that moment. Something rolled downhill that day....