Generally on a balanced field takeoff you should be able to achieve 35 feet at the end of the runway with a failure at V1. They clearly would not have made that. The question is did they get bad data, load the wrong data or rotate very slow. I have seen bad data more than I care to admit. A bit of cargo gets omitted or a incorrect temp is imputed ect.. Does Ryanair use a central load planning or does the crew do the weights?