Many times? I can only remember 2-3 times,(vs Parma, I forgot this one, and then against Inter) Actually Balotelli made a clear dive, and he didn't even hit him, But he gave the refree a chance by getting red with raising his hand to high. 89 minute? yeah that means we still had 6 minutes to score 2 goals in, thats possible, look at Manchester City did it 1-2 weeks ago.
And you're right, it may be his first time, but it doesn't change the fact that he leet his team down.