There is a big difference between "if I believe it was intentional" and "unless I saw something so unquestionably blatant". The latter would require another act other than the catcher hitting the batter runner in the back with the ball. You ejected the runner in your example based on her action of elbowing the catcher (blatant UC), not for sliding hard into her, which may or may not be UC based on whether it was intent to harm or not, but there was no evidence to support UC/ejection without the elbowing under the chin. I completely agree with that.