Well, the fact that that one even triggered you back is part of the heart and core of BPD, and if could easily deal with it, thwart it and ward it off, it wouldn't be much of a disorder ---- point being, I think you had a 'normal' bpd reaction.
There is a sense of betrayal, the realization that for a rather long period of time he was engaging in something he claimed to be against. The 'over' reaction is part of BPD and it just sucks and I wish I could offer you better words than what I just did.. but that's all I've got. (hugs)