Join Date: Jun 2017
Location: Never Never Land aka St. Croix Virgin Islands
Any situation that causes cylinders of any internal combustion engine to be filled with coolant or oil, it is mandatory to pull a plug or injector and turn the engine over, prior to attempting a start. The condition is called Hydrolock and the fact that liquid, unlike air, cannot be compressed, results in bent connecting rods.
That said, OP didn't report how long the bike continued to run while on its side and if it ran until someone shut it down or shut down of its own accord. Also missing is how long the bike remained on its side before being righted and and the attempt to re-start was made. He did report cylinder filled with oil....see paragraph one.
I would think that a qualified engine specialist could use a dial indicator to measure the height of the piston face and quickly determine if the associated connecting rod was bent.