I don't believe this. Not because I think we're nice guys and wouldn't do it, but because it doesn't make sense.

To begin with, this type of mass murder campaign is high risk, there is a very good chance of getting exposed, so it would normally be undertaken reluctantly and where the consequences of not doing it would be unacceptable. If they had said the victims were Iran-bound nuclear physicists or other WMD specialists it might have made sense, but Mossad, for one, would never expose itself like this to murder Phys Ed instructors and humanities profs.

Second, there is just too much information available. Pie charts, statistics, way too much for such a clandestine operation conducted by
one of the best intelligence services in the world.

The source is also highly suspect, although that alone is not sufficient reason to rule it out. Even a blind pig can find water sometimes.

I can't rule this one out completely, but in my judgement, it's probably not true. There is also the possibility that it is partially true, some of the Iran-bound nuke profs may have been wasted, and the rest of the evidence is manufactured to embellish the tale, but that is just speculation on my part.