Hang on! This post started because Alex W1 had a problem with KLM; now we're in the realms of incorrectly loaded aircraft and reportable occurrences. This is ill-infomed anorak speculation IMHO (go ahead and report me!).
I have submitted and investigated MORs several times in the past. I'm well aware of the circumstances requiring a report and the applicability of CAP 382 (those of you quoting CAP 382 should read paragraphs 5.1 & 5.2 of the document).
I think KLM Ciyhopper now operates under a Netherlands AOC. If you were talking about occurrence reporting, you may want to find out what the Netherlands' Competent Authority has determined is an appropriate method of reporting (See Part M, EU-OPS and Regulation 216/2008). EASA has provision for any concerned party to raise a Form 44 and submit it direct to Koln; this form is primarily for non-EU Part 145/Subpart G organisations but does allow anyone with concerns to use it.