Official Ryanair Cabin Luggage
 

Note
*As this Samsonite bag is softsided, if over-packed it may not fit into Ryanair’s baggage sizers and in such cases Ryanair will require it to be carried as checked-in baggage.

They also don't say how much the bag weighs empty. If it's typical O'Leary it probably weighs 10kg empty

Looking at the bag, and remembering the luggage sizers at the airport that Ryanair uses, I would be fairly suspicious.

I have experienced this problem with a soft suitcase. I was flying with easy jet though an as I was about to pass through the gate I was stopped and asked to fit my carry-on in the size guide... after some struggle I managed to fit it in!

Looks like that news article has been removed from the site.

LoL , that link is 4 years old.

Ha! I didn't even notice the date stamps!