I believe he felt inadequate when we broke up, we broke up because of HIM and how he IS, so he lashed out... a narcissistic injury:

"Narcissistic injuries are almost always projections, which is the misplacement of the narcissist’s unconscious self-hatred onto any person who they experience as threatening. Feeling “bad,” “broken,” and/or “never good enough,” like they did as a child, is simply not an option for the Personality Disordered narcissist. In actuality, projections are dissociated feelings of self-hatred and self-loathing, that are attributed a person who threatens the narcissist’s veneer-thin self-esteem. In other words, projection diverts the realization of self-hatred and core shame by transferring self-judgment and condemnation onto the activating or ‘injuring” person."