I'm not sure there is a 'common policy' for IRROPS, it's also unclear how PAX bags were tagged (i.e. to the final destination on the next-day flight or to the final destination on the original booking), if the former than I would indeed expect KL to refuse (or ask for 275€ fee), if the latter then it sounds like a reasonable request, whether the reason for refusal was racist or not I guess we might never know