In my experience entering the Nordic countries with a UK passport does attract greater entry scrutiny than other Schengen area borders in terms of both the 90 day rule and purpose of visit with Sweden being the most inquisitorial and pedantic. Helsinki can also ask a lot a questions but they seem more geared to transit entry due to the connecting flight model Finnair use.

Extra questions crossing the border in Sweden, Norway or Finland with an overnight connections or when I've entered Schengen through a different country border so they can't easily reconcile the length of time spent in the Schengen area is typical. I also notice the Nordic border officers take a lot more care ensuring entry and exit stamps are inserted neatly and adjacent to one another whereas Mediterranean country officials seem to place stamps randomly.

Refusal of entry sounds like this particular immigration office was taking it to a higher level. Did the Op's husband have a confirmed hotel reservation for the night in addition to evidence of the departing flight the next morning?