As far as I can recall from real games last season and in any recent seasons, the overwhelming majority of time outs are implicit, and the umpire does not actually call or indicate time out. Those are the hundreds of time outs that occur between pitches, most when the batter steps out of the batter's box.
Stepping out includes placing one foot outside the box. If that's not to suggest, imply, request ... time out, then what is it? The umpire just stands there like a doofus (someone who does not have a clue). The umpire doesn't indicate anything.
Likewise, the pitcher also just stands there like a doofus. If the pitcher had any brains, he'd throw one right down the middle.
If this happened, what would the umpire do? If the umpire protects the batter, then the pitcher should contend that the umpire had not called time and that the batter was in jeopardy and the umpire should call a strike.
If the umpire called a strike, either initially or after being prodded by the pitcher, the batter would have no recourse. Abandon your box at your peril.
And all this would be done with the rule that requires the pitcher to pitch within 12 seconds with no base runners. You know, one of those rules they don't have time to enforce.