Could this have done damage to the bike?
One thing that can happen on all engines having multiple cylinders and a catalytic converter is this:
N-1 cylinders are firing, providing hot exhaust to the catalytic converter
The remaining cylinder is not firing, so the raw evaporated fuel goes to the catalytic converter
The fuel burns in the catalytic converter ...
If penetrating fluid, time and rocking (as described by Nick C) do not work, you may need to take it to a mechanic who can heat up the plug (usually with a torch) to get it out. With all of the plastics in a modern engine, you don't want to do this yourself as it can be tricky to keep for doing more damage than you are fixing. Good luck!