However, there are lots of "strange" references that make no sense in a Pathfinder context. (These are all from memory, so apologies if I get some of the details wrong.) Half Elven grooming rituals? Making a point of mentioning that a wizard wields a gold orb. Some monsters changing tactics when they get "bloodied". Someone helping out his friends with "a series of leaps and jumps" but not having any ranks in Acrobatics? I think there were other references to rituals as well. None of this impacts on my ability to run the adventure - but it might have, and gives me something additional to think about, which as a Pathfinder GM running a complex adventure, that's not something I need.
(And it could have impacted on the adventure - I read a 5th edition adventure where the body of a shark-like humanoid is found; later these turn out to be sahuagin, which have an affinity for sharks but don't much look like them. Turns out this is a conversion of a Pathfinder adventure featuring Adaro, which are shark-human hybrids but don't appear in D&D.)