some thoughts .... assuming your theory is on track .... ...
Could Sarah have been transported beyond the seas? If so marriage was ended when she embarked ....
Could Sarah have quit the marriage and was not known to be alive .... Seven year rule ...
have you looked for any children for John and Sarah ... if none, she may have quit and gone beyond the seas of her own accord or stayed local but joined a convent or retired to a nunnery
Outside the square thinking
JM
Re Transported under a sentence I have not yet found her in New South Wales 1814-1824, but still looking.
Re not known to be alive - please use RChats search option for the year of 1604 as the keyword... plenty of threads will give you the relevant wording to confirm the relevant statute law
If you cannot find any children, then possibly there were none born alive. Sarah may have died in child birth.
Bachelor on next marriage .... The information on parish registers can be 'fluiid" in the degree of accuracy. The clergy's first duty was not to foresee that 200 years later there would be questions to answer that were posed by people who are interested in family history. Clergy may have recorded 'bachelor' without even asking John HUNT. Clergy were supportive of marriage over criminal conversation.
When looking for Sarah's possible death .... as a burial in a churchyard ... HUNT can be mis-transcribed ... M or W or F or TH for capital letter. . And the second letter could be any vowel and as for the final letters ... u or r or S or e or m or l and so HUNT could be indexed as Wail or as indecipherable ... or worse perhaps the burial register is not extant ...
So when looking for burial perhaps best to search for her first name Sarah rather than her surname. Also try Sally and Sara.
A bachelor was simply an adult male who had no wife and children with him in his domestic circumstances.
JM one finger typiste so edited to sort spelling and grammar.