Yes you can be friends. he was not your therapist, psychiatrist, psychologist or medicaal doctor. Also even if he had been the professional in charge of your case it has been 2 years since he has been in charge of your case. here in the USA the majority of the USA ethics law time frame is that the client therapist relationship can turn over into a friendship one year from the date of the last therapy session. If by psych tech you mean therapist then check with your state board of certified and licensed clinical social workers to make sure because there are I think 5 states that require 2 years from the last therapy session.. in which case you are still in the clear because your post says you were hospitalized 2 years ago.
As for how do I deal withseeing my therapist out in public - I would wave and or say hi there. LL and I discussed this before when she say me at the library. I didn't notice her but she noticed me. I told her I have no problem with her coming up to me in public and sooner or later the two of us will end up seeing each other out in public anyway she sometimes shops at the same grocery store that I do.so like I told her if it happens it happens my friends all know I am seeing a therapist so no reason to hide it. Its usually those that are making a big deal over not being seen and so on in public by their therapists that people are going to notice just from watching the self conscious behavior. But no one would notice anything out of the ordinary by two people who stop shopping or researching at the library to say hi to each other.The more self conscious you behave the more conspicuous you are. besides Ive been as public as anything in the past why go secrative now. right. LOL