Screaming pitcher

[CecilOne]

No, this has nothing to do with velocity.

The pitcher screamed/screeched on each pitch after releasing it. The pitcher and coach said it was nothing more than a normal exhale, like other pitchers grunt as part of their effort. This pitcher's "sounds" did not occur until the ball was more than half-way to the plate and the batting team complained that it was a deliberate distraction.
The umpires warned the pitcher not to make the sounds after the ball was half-way to the plate or they would consider it UC. The pitcher eventually was ejected for this.

What are your opinions of the batters' complaints, umpires' judgement, rules basis, etc. for this sitch?
Would you respond differently under various rule sets?