Pilots from other European bases were sent to the UK as strike breakers to break the strike. They should've known better. They could've called a strike or just suddenly become ill to avoid doing their UK colleagues flights. All you need is some guts to back up your colleagues on strike. Whatever the benefits UK pilots could achieve is going to benefit them, too. Shame on them.
UK pilots needed their help. With this kind of behavior things are never going to get better at RYR. Everybody has to stick together.