The suspision and anger are v natural and fully understandable.........but they are not your friends. You need to part company with them for your sake.
I could repeat loads if stuff we both have read here but you know it already.
If it bothers you to that point, your gut instinct is probably right. That is what sandi would say. On the other hand it could have been anyone that rang. We tend to over analyses and put too much emphasis on some stuff.
I'm sorry this is difficult for you, but if there is EA/PA sooner or later it will have to come out. No other way of healthily getting past it. Brace yourself and prepare your boundaries. But as cadet would probably advise DO NOTHING at least until you have proof.
You'll get through this.
R 25 years M 14 years S11 & S13 Working on it alone since Oct 2014 M in trouble a lot earlier (~2 years) Feb 2016. 1st R chat in a yr. Next R chat Aug'17 Still together