It's not that the AI was suiciding, but it literally did nothing. I mean it - literally - it stood at the middle of the map (it's the 2v2 map) between the two Fortresses and did nothing.
Every time it resurrected, it went back there and stood there again. In a nutshell, I was able to hold them back before they realized it's standing at the middle (it was in the side passage) and started killing it every time.
Before he left we would've won. It was a really nice combination too - Frost TB and Fire TB, both auras. It was very easy to run away from the opponents because of this.