Hi, sporeloser THAT VIDEO IS CHAULK FULL OF MISS INFORMATION, the good news is nobody ever died from eating the wrong tree. On the other hand proper mushroom identification is vitally important. The saying goes ” All wild mushrooms are edible, some only ONCE.” There are a couple real easy trick’s to identifying Elm bark/trees.
DEET, really doesn't prevent tick's, and normally if the tree's are leafed out enough to "flap in the breeze like sequin's" you are on the tail end of prime picking season.
There is a lot of accurate info out there, just be careful, Ok.