Glad you've got it fixed.
The EGR valve isn't accessible without taking pipes off. What did this fella actually do - waggle a lever on the side of the inlet trunk next to the EGR vacuum "saucer"? If it was an external lever, that's the anti-shudder valve, which is only supposed to shut for a few seconds when you turn the engine off. Stuck shut, it would definitely prevent your engine from starting again - no air. The extra suction may have been enough to cause the starter to fail to turn the engine over.
I'll try to remember that if I ever have a mysterious "won't start" issue
