I was alerted to this thread by a couple of users and seeing my comment on the first page - point still stands. The transplant is really not remarkable, especially when you consider his starting point as a Norwood 3 with reasonable thickness.
I think it's definitely a failure of the surgeon in terms of hairline design but Peterson himself is just a hard case too. Massive high forehead,really long face, old and not good looking. The transplant doesn't look convincing if you look at it cosmetically, it's see through in the transplanted areas and behind the areas too, even in moderate lighting. The high straight line just creates an unaesthetic unnatural look too. Despite sometimes showing his white hair which matches the skin the diffuse look is apparent. He has a lot of donor and probably needs another go, dense pack and with a better surgeon.
Important to comment that it's more than good enough for his age and I doubt there is much difference to his look before and after surgery in terms of impact. No temple points either. I believe idealforehead also pointed this out and several other users. But Peterson would admit himself, he was never aesthetic and purely an academic so that's that.
It's harder to look good as a guy in his mid 50s but Peterson will get the "ageing well even if not attractive" tag which is still something. Even through that, as an ordinary guy he would remain somewhat relevant to women and a little younger perhaps. His skin is not in great shape either and looks weak.
As an older man to stand out in your age group and much below, you really need your looks to hold (assuming they were there to begin with), decent body, no hair loss (unless you're black) and excellent skin. Also adapting the hair colour for an appropriate age look or slightly younger.
David Easter is still playing roles with girls half his age in soaps and is around Peterson's age. Scott Maslen is a decade younger than both of them but hard to imagine he'll age like that.