I just watched this again and I think Perez just got carried away with himself. Kimi however sort of half blocked and did it too late. He should have known that he would try the move again as he had done it on him before. I reckon Kimi thought, "Well, he won't try that again", and then when Perez did go for it again he thought, "Well bollocks to that, you're not pulling that one on me you little shit", and then squeezed him late.into the move.
In conclusion, Perez was taking the piss with attempting that overtake again but Kimi was the one who caused the colision and I'm sure he fully expected a collision as he moved over to the right. Perez was over racing and Kimi was driving with red mist at the audacity. 50:50, the scamp and the bully.