Don't need specifics, but was this high school?Almost always, no.
I can think of 3 games we've had where the umpire(s) absolutely determined the outcome, and in two of them I'm almost certain it was intentional.
Our most recent one had an umpire who was calling balls bouncing on the plate strikes for our batters (and he wouldn't allow them to move up beyond the front of home plate even though I explained to him how far in front of the plate the box goes -- there were no lines). He literally handicapped our batters and then called pitches they could not hit. Oh, and our pitchers? Unless they were firing it through the eye of a needle, they weren't getting calls.
Funny thing is he said he wanted hitters to "be aggressive because I'm aggressive calling strikes."
If I had to estimate, there had to be at least 75-80 pitches in that game that went in one team's direction. It was that bad, and I'm probably underselling it because there were entire at bats where after each pitch my catcher would look at me for the sign and give me the "that was a strike" look. We didn't draw a walk the entire game (the only other game this season we didn't walk was when we faced a pitcher throwing 60 and she mowed everyone down) and half their pitcher's pitches didn't get beyond home plate. It really could've been more. He made a couple other bad/curious calls, and a couple instances where he didn't know the rules (in one case he said "oh, you want to get technical with the rules?" when he wanted to call a player out for slinging the bat).
I think if our players had made every single possible play there was to make and gotten a base hit on every single actual strike they didn't get a hit on, we probably could've still won. But I also think it's unreasonable to expect perfection in order to overcome an umpire who is, for reasons I can only speculate on, is doing his best to help one of the teams win.
But short of something like that, a truly egregious example of an umpire going out of his way to help one team win... no, umpires don't really control who wins.