Matty Kennedy scored from the spot after Dallas penalised Hearts midfielder Peter Haring in a challenge with St Johnstone substitute Liam Gordon.
Video replays showed no contact, but Berra spoke to the referee and was assured there was.
“It’s pathetic,” complained the Scotland defender. “I spoke to the referee and he said: ‘It’s clear as day’. I’m sure our media guys will put the video up and we will see.
“He just falls down and the ball is going away from goal. Our player controls it at the edge of the box.
“I need to watch what I say but it is infuriating after getting an offside goal against us at the weekend [against Rangers].
“Don’t get me wrong, we aren’t the only team it happens to.”
Berra added that even slight contact cannot be avoided in football.
“Are you not allowed body contact in the box, seriously?” he questioned.
“You just fall down and it’s a penalty.
“The ref was 30 yards away. Did he give it, or the linesman?
“It’s the same things.
“I know it’s the toughest job but give yourself a chance.”