Ann: Symons Hill (updated)- Pyrrhotite and Chalcopyrite Sulphides, page-14

But most pyrrhotite is produced by metamorphism (where rocks are subjected to high pressure and temperature deep within the Earth's crust) of sulphur-bearing sedimentary rocks which is the case here. These sulphide occurrences often suck up other metals like copper and zinc and so you will often get a sniff of these, but these will almost always be uneconomic red-herrings.

Yes, pyrrhotite is also found with pentlandite in nickel deposits.....but these cases are far, far less common than the occurrence of pyrrhotite in metamorphosed sedimentary rocks as described above.