Originally Posted by Infidel79

The passage you quoted from the Park tool website is indeed a bit confusing, and I think poorly written. I think what it means is that if the cable is too tight, then the inner limit is thus established by cable tension, not the inner limit screw. Therefore, if the cable tension is reduced (i.e., "if the inner wire tension were to change"), then the inner limit would also change, up until the point at which the derailleur encounters the limit screw. I think the part about the chain falling off the rings assumes the limit screw was not adjusted properly in the first place, and the cable tension subsequently becoming too loose.

Since we're talking about not being able to stay in the big chainring, this explanation doesn't seem to apply to the current scenario. The only way a limit screw coming out of adjustment could cause the OP's issue is if the outer limit screw were to spontaneously tighten itself from road vibration, thus preventing the derailleur from reaching the big ring in the first place. I think this is highly unlikely. A poorly installed cable housing is a much more plausible scenario in this case, as has already been determined.