I am still having a hard time understanding how a leaky rear main seal on one side of the flywheel allows engine oil to reach the other face of the spinning flywheel??
Leaking oil that may hit the front side of the flywheel is going to be flung around the whole bell housing, then will run along the top of the bell housing, dripping onto the clutch pack, and easily soaking both surfaces. Even if it only got to one side of the disk, you'd loose nearly 1/2 of the friction area.
Usually oil on a friction material like clutch or brake shoes will tend to make them grab. But I know that diesel fuel will cause a clutch to slip. I once lost 14 gallons of it thru the clutch on my PowerStroke. It did finally stop slipping in top gear after I got the leak fixed. I initially washed it out at the local squirt-a-car, using the soap cycle and then rinse from the same source point as the leak in the engine valley.
Sorry about the bum ankle.