lol that's a cool story you probably damaged the rings and cylinder wall by force starting it without taking some precautions first. If you have an engine that has sat a long time you definitely should pull the spark plugs and spay lubricant down the holes. Let it sit overnight. Then gently try and turn over the engine by hand and see if the rings are free or not. Something sitting so long the ring tend to stick to cylinder wall and turning over the engine suddenly can cause them to damage the cylinder wall and damage the rings. So while running down the hill you probably did some damage but it was moving fast enough that it could get enough compression to run while you had it running. After you stopped it and attempted to start it again there would be less oil on the pistons as well as any damage greatly reducing compression and preventing it from starting.