There two types of trailer boaters - those that have left out the plug and those that will. I have more than once.
I saw a guy at Misery Point back his S-10 into the water far enough that water came in when he opened the door. In a hurry to go shrimping. He did manage to drive the truck out after launching his boat.
When I was a kid, my Dad backed the pickup down and unloaded the row boat. As he started to move the truck up to park, he slid in the loose gravel and bumped the boat out into the lake. Luckily, the only other guy on the lake saw it happen and towed the boat back.