Even if it were true, audits wouldn't catch alleged misvaluation of assets for lending (and other) purposes. So, yes, weird.
Incidentally, tax returns don't include 99% of the information for which Democrats were and are looking so I always thought that rabbit hole was strange for them to fall down. I think it was more about embarrassing President Trump for not being as rich as he says he is, which is also why he doesn't want to release them. I imagine he cares more about the portion of the press conference today that talks about his assets being (grossly) overvalued than getting sued.
And Lehigh is a good dude. I just do fewer drugs than him.