picton - this is nothing new regarding easyJet and you have no standing so your 'colleague' will have to take their medicine and just go and do what they are paid to do.
UK pilots have always been called out at very short notice to cover the foreign bases whenever the fellow bretheren could not be bothered to turn up for work, for whatever reason..!
Andy Harrison used to send out lovely warm emails to the pilot and CC workforce every time the Frogs went on strike (2007/2008/2009/2010....get the picture) informing that it was mandatory to go and then went in to the legal coverings as to why you could not say "Non..!"
Enjoy - lovely cheese platter in The Sheraton