LaLoba It is even more disturbing than I realised - I misunderstood and thought that your husband was with you in the treatment room when this guy walked in on you.
Definitely get support from the Wales NHS equivalent of PALS.
However, from what you have said in your follow-up post I would strongly recommend that you consider raising a concern with the HCPC.
The HCPC would inform the Registrant and the employer that a concern has been raised. This might result in the employer putting any action under Disciplinary or Performance Procedures "on hold" until the HCPC has made a decision. However, if this is being dealt with as a "systems problem" then, depending on the HCPC decision, the employer might be forced to deal with this under the Disciplinary Procedure (as a Conduct issue) or under Performance Improvement procedures.
The HCPC would anyway be meticulous in seeking to establish whether or not there is a "systems issue", in order to determine whether or not it would progress a concern as arising from a Registrant's breach of Standards.
If the HCPC believes that there is a "systems issue", rather than or in addition to a Professional issue, then the HCPC would report this back to the employer with recommendations to improve the system. The HCPC does not pull its punches when it finds that an employer is at fault and inadequate systems or supervision put the public at risk.
You are welcome to copy and paste whatever you think would be helpful from my posts.
I have had dealings in the past with the HCPC in both a Professional and Trade Union capacity (not a personal capacity). The HCPC remit is to protect the public and it has active involvement of lay members of the public as part of its statutory structure. It has no remit or agenda to protect the employer.
An NHS Trust has a corporate responsibility to protect its reputation and assets. To give you an idea of what this means in practice: the standard Risk Assessment process for a Trust where I worked rated "the worst thing that could happen" as "a Question is raised in the House (about a death) and is reported in the Press", ie. rather than the death of a patient itself.
If, as you suspect, this guy has already shown problematic behaviour and other staff have been concerned then there clearly is a "systems problem" in that it has not been dealt with adequately. That does not absolve the Registrant from failing to meet HCPC standards.
Taking this outside the Trust might well be a great relief to other staff. They might have been dissuaded by the employer from raising a concern with the HCPC themselves, ie. on the basis of a reassurance that "it is being dealt with".
Everything else being equal, I would expect that raising a concern with the HCPC would be less stressful than raising a complaint through the NHS system.
Two caveats: Trusts differ in how well they deal with complaints and your Trust might be better than average; in this particular case the Trust might already have reached "tipping point" with this individual so the issue might be resolved more quickly than an HCPC concern.
And a final reminder: if this guy gets wind that a Disciplinary Procedure might be in the offing then he could just up sticks and move on with an unblemished record. The Trust might even give him a glowing reference to get rid a problem about to blow up.
Only the HCPC can hold him accountable wherever he works. It would still look at the systems currently in place in the Trust even after he has moved on. However, if the only "red flag" is an NHS Complaint then the Trust might be tempted to "blame the bad apple" - leaving a weak procedural and supervisory system vulnerable to exploitation by the next "bad apple".