
Anything is possible.......but are they sure they didn't have a 1-7/8" ball with a 2" hitch, and then one day the trailer coupler's "toe-plate" (or whatever it's called) that goes under the ball wore down, or got loose enough, to pop off the ball? A 1-7/8" ball will work on a 2" hitch most of the time...until it doesn't.
I'm hesitant to put any dielectric, like grease, on the ball hitch as I'm often relying on good metal to metal contact for the negative ("ground") return path back from my trailer lights. Heck, sometimes it takes a few miles of going down the road and making turns to wear the rust off before the lights work if its been sitting for the winter.