So it's inconceivable that he may have fudged his CV? Or embellished his ability during the hiring process? Because nobody has ever been economical with the truth in order to secure employment, have they?!

You don't know how he was treated, you don't know how he behaved at work, you do not know the full story. Yet again you are just rushing to jump on the 'blame the school' bandwagon, rather than ask objectively for more information or even consider the ex-employee may have a disgruntled score to settle...

I met more than a few tourist-teachers who weren't up to the job of teaching and felt picked on by a school because they were asked to perform better. The fault here lies with people like you lot who insist teaching esl is not important and can be done by anyone, thus encouraging people who shouldn't set foot in a classroom to do so in.order to secure a visa for their extended holiday in Asia. Nd then when they are asked to actually teach, fail to do so adequately and are fired for either poor performance or inappropriate conduct (missing classes because they're hungover, turning up late, missing meetings)... Whereby you lot rush to their defence brandishing the tired warcry of "rubbish school!" and blaming everyone possible except the teacher themselves!

Yes, sometimes the school is bad. Equally sometimes the teacher is and it deserves more consideration than mindless agreement just so as to fit in with your views.