You can't wait for something to happen.

You MUST go on the offensive straight away.

The stakes are too high to take risks and the biggest risk is letting some idiot jobsworth play god with your son's future based on some spurious whim.

Their attitude is completely unprofessional.

You should have spoken straight away, and there should be some established pattern of possible abuse before anyone is even allowed to even raise it as a potential issue.

You MUST draw attention to this on your terms and make this person accountable or you may end up having to fight some idiculous case on thier terms.

You are currently (completely understandably) bricking it as you are afraid for your family.

The system where you are may not be perfect, but it isn't the third reich and individuals like the one you are dealing with do not have arbitrary power.

I didn't say it before, but I agree with all those who have said to get legal advice.

I would also suggest you do some of your own research and find out if there are any organizations that help in cases like this.

With regard to the second part of that last point, be careful that the organization is legit and not associated with genuine abusers. (An example in the UK would be fathers for justice who had to close down because their membership was becoming increasingly made up of guys who were genuine risks, so the organization was losing credibility)

The key is to be informed so that you can make decisions based on satisfying legal criteria rather than your own moral code which, valid as it might be, will not save you in court.

Take care and don't worry about the trolls etc