I'm not at all surprised to read about a TSX out of near anything leaving a minimal size exit wound. That has been my experience with them as well on several deer. Near any bullet will kill deer with a good shot placement, but in real world hunting good hits don't always happen. I want a bullet to do a lot of internal damage and exit with a large enough exit wound to provide a good blood trail and drt is even better. If a bullet fails to exit, that is a fail to my way of thinking. A quarter size hole through both lungs instead of lung mush with a 140 grain TSX should have told me something, but it didn't register with me until I lost a nice one using that bullet. Faster opening, larger mushrooming bullets have done way better and I'd be reluctant to try a Barnes anything again. Barnes didn't come out with the TTSX and LRX because the TSX was working well on lighter frame animals.
