Uhm,I guess ANYTHING is possible, but highly unlikely. It will flood the engine if you start it/stop it/start it/stop it/ etc say....letting it run for maybe 3 seconds and then killing it and starting over. Sure, eventually it may flood it doing that (it does on my GSX-R while screwing with PCIII settings) but starting it and letting it get to 138 degrees then killing it........no, that in and of itself will not foul your plugs.
Is there a TON of blow by on the rings? That would do it, but it would have to be so bad that it surely smokes like a two stroke. LOL.
If it's running wayyyyy rich, that too would do it. YOu could lean it out and see what happens (as described above).