I understand, but the good factor of being friends is that you can seem to get through most things together. When me and my partner argue, we tend to take it as an argument as if we were friends and never get our feelings involved and less they have to be, asif we were friends - and that way it never affects our boyfriend and girlfriend relationship.
What I mean is, being friends can have its benefits as well as its doubts, you clearly know him well and vice versa so just talk through it, you dont have to be afraid of him playing mind games with you because he's a friend and there is no need for game playing. Tell him straight out how hurt you are, and im sure he'll support you through it.
These kinds of things happen to everybody, even if you weren't friends, and even if he did go off which is horrible in itself, it doesnt mean he is a bad friend and definately doesnt mean his intention was to hurt you. Just move on forward and remind yourself that okay, he wasnt perfect for you in a relationship, but you must like him enough to be his friend, and i dont see why your platonic relationship should be stopped because of it.