IS has article about Finnair not paying compensations. Only in Finnish.
Toilets got full due to 1h20min on the ground due to technical, flight made extra stop to empty toilets and get more fuel.
https://www.is.fi/kotimaa/art-2000011576149.html
Some main takeaways:
Only 4 persons out of full A321 applied for EU261 (most likely AY said its extraordinary and people didnt even bother)
and
Ilta-Sanomien selvityksen mukaan Finnair on jättänyt viimeisen viiden vuoden aikana lukuisia kuluttajariitalautakunnan suosituksia noudattamatta tapauksissa, joissa lautakunta suositteli hyvitystä asiakkaalle.