Know your equipment and use it accordingly. Don't trust anyone to tell you it is "OK". Not my wife, not my dad, not my kid, not my brother, I get out of the truck and look myself. If the jaws are around the kingpin and the bar is locked with the safety pin in the correct position...verified by me...it is good to go.
Yea, I said I do NOT do a pull test but I do watch it in the rear view mirror and if the truck would move without the camper following by a few inches I would stop immediently. Always be aware of what you are doing and what is going on around you.