Farmpilot,
All depends on what one means by oiled-up windscreen. In the present issue, it seems a large portion of the engine oil ended up on the top cowling and windscreen. I'm not sure how many quarts of oil are in the continental/lycoming C210 engine but even 1 qt spread on the windscreen is sufficient to block all front vision.
As said previously, something similar happened to me on rotation in a C150 and I had to taxi back with my head outside as vis was close to nil.
Regards,
ZS-NDV