I sure hate to see you get swayed by all these other comments. Sure, there's always an outside chance something else caused the clutch to fail, but 9 times out of 10 it's a straightforward repair and a very common failure on the direct drive machine. I have underwear older than most of these guys, but you can listen to whoever you please.
Once you get the tranny out, it will be obvious if oil had anything to do with it or not. You don't know until you get there, but hopefully it will be a simple repair for you.