Cecil,
Just call it as you see it. You're trained, seem to be skilled, not looking for boogers - if you are satisfied with your judgement, go with it.

Call your game. If you are convinced it's an IP and you're consistently calling it on all the pithcers, call it here.
Heck, don't overthink it. Trust your instincts and don't let a coach, player, fan or situation get into your head.

Again, call <b> <u> YOUR </b> </U> game.