I haven't seen the advert but I would be surprised if JEFTS had to resort to advertising in Flight to get their staff - you can't even send them a CV normally, and on the very rare occasion when a job has come up it's tended to be word of mouth recommendations or they'll invite someone they want to apply.
There are also quite a few instructors (such as myself), with a high-ish amount of time instructing RAF cadets, who are floating about on the job market at the moment following the demise of the RAF Flying Scholarship scheme. I know for a fact that there were no vacancies at JEFTS as of a few weeks ago, and in the current employment climate I can't imagine vast numbers of pilots have moved on since then.