I reckon you did good thumpango, the walkround is a serious part of the pre flight and youve just demonstrated why.
Mildly amused at your CFI saying that they dont usualy check them. Ive got two PA28 checklists, and a PA28 Pilots manual, and all of them quite clearly list the plug leads as part of the engine compartment check.
I have seen the brading a bit thin, but not worn to excess and Ive certainly never had a lead come out of the plug! I dont pull hard on them, but I sure as hell make sure they are connected to the plug ok.
What do you use as a checklist for the walkround?? Is it the clubs own type of checklist, or one of those say produced by AFE?
Regards,
Speedy
(edited cos i carnt spel)