Interesting that you put it in terms of sensitivity. I would put it in terms of utility, respect, and virtue.
It wasn't coaching, was it? Taking shots at your own players has no utility.
It wasn't respectful.  I thought Fleck believed in Respect.
It doesn't demonstrate forbearance, kindness, patience, or self-control.  There's no virtue in taking shots at your players.
What it looks like is an exasperated coach venting at a player. To what possible purpose except embarrass him?
I doubt that Fleck or anyone in his household reads this board, but I hope I'm wrong.  I hope he knows that his Forget About Me I Love You BS is wearing thin.  In this instance it's so thin it's transparent.