Ive done the drain plug thing a few times. One time I had a coworker with me. We were about a 1/4 mile from the launch when he picks up the plug off the deck and asks is this "trash"? Had to make our way back and put it on the trailer to drain, it took over 10 minutes. I almost sank it!
Another time Bigred had launched me in the mohawk in his boat...330am in the morning...I ended up getting the boat stuck in shallow water right near the dock and in my haste to get unstuck, with the motor trimmed up, roosted lance, my buddy and two other dudes standing near by. I wasn't use to how quick the yamahas throttle was compared to my looper. Boy was there laughs after that.
Ive also seen someone drop their rig off a roller trailer and saw another guy in peril when backing down to launch the trailer frame broke, specifically the cross beam and slammed his boat right on the pavement. Obviously not using solid judgement the guy pushes the boat into the water, launches, parks his trailer like nothing happened and goes out on the lake.