Don't worry, I know the value of latches, and also use padlocks as pins, there when you need them, and useful as pins otherwise. I make sure the ones on the doors to the box trailer match the one on the hitch, and the other trailers I have, they share a key...
I don't know the ol' man very well, his son (my friend) and I share concerns with this matter...
Argueing with an old man who is convinced he latched the trailer, well, I come across as arrogent enough most of the time! I'm just gonna double check as much as I can if this situation happens again... If my truck wasn't in the shop getting a trans, we'd have been using my truck, and no old man!