@thus_spake_z Been reading about this. Seems there are 2 important issues in this case:
1) the panel considered that sexual relationship was consensual and started after therapy had ended as a mitigating factor.
2) The HCPC sanctions policy allow for either striking off in most extreme circumstances (e.g. abuse) or, for lesser offences such as this, a maximum of 12 months suspension.
In this case the psychologist’s behaviour wasn't considered extreme enough to warrant striking off as the relationship was consensual and started after therapy had ended, so he was given the next most severe sanction (12 months suspension).
I’m not saying I agree with the decision, just that this appears to be the reason for it. If you ask me, the HCPC sanctions policy needs reviewing.