That's really a disappointing response. The jury's verdict is truly irrelevant. Whether the subsequent treatment was appropriate or not is irrelevant. Even the exact cause of that particular player's inability to withstand the gassers doesn't really matter. Nor does it matter that other players were able to do the gassers without harm.
What matters is that Max Gilpin couldn't do them that day without collapsing.
What matters is his expectation of being dismissed from the team if he didn't keep doing the gassers. Without that fear and expectation, he would have stopped sooner.
"Until somebody quits" isn't isn't just "against what coaching is about".
It's dangerous.