Sorry - didn't snap any pics of my bad tank.
The torn plastic was at the radiused corner, where the flat top of the gas tank turns from flat horizontal, through a tight radius, into the vertical round filler neck. Some tanks were thin in that area, on one side or the other. My tear went about 1/3 of the way around the base of the filler neck.
Dealer said to loosen the gas cap at the end of every ride (not enough to leak gas in your trailer) and especially over summer, so the cap doesn't "stick" to the tank and cause future over-torquing to loosen.