He ignored her, paid no attention to her, and pushed her away. He had to escape from her, he was suffocating. He wasn't into commitment and he wasn't seeing a future with her, but when they finally ended it, why is he the one getting mad about her new boyfriend? Why was he the one getting her? Shouldn't it be the other way around? 

He saw her broken and fragile. He wanted to do everything to mend her broken heart. Something he wanted to do with a caring heart, he realized he had done it with a loving heart. Helping her was a choice, falling in love with her was automatic.