Content?I would say that as long as the third doctor is content, after reading the other doctor's notes, that they have come to a good faith opinion, he hasn't acted unlawfully. He has acted unprofessionally and might be liable to sanction. But there is no criminal offence, either in the Abortion Act, or the Offences Against the Persons Act, that he has committed. If after carrying out the abortion, he wilfully doesn't complete the HSA4, then he will have committed an offence, and will be liable for a big fine.
As long as a HSA1 form has been filled correctly and dated, yes.
Have you bothered reading the Act and the Paliamentary report I linked?