The OP didn't contribute to the idiot's education. Road rash contributed to the idiot's education.

Some cyclists just don't know how to ride an MUP. I'm a strong opponent of one-size-fits-all 15 mph speed limits, but there are times when you just can't safely go more than a few miles an hour. Last week, some roadie passed me going about 25 mph. I found him 1/2 mile ahead nursing road rash from going around a corner too quickly. (And yes, I offered help, which he declined.)