Too ethical for Coburn?

Sen. Tom Coburn (R-Okla.) thinks the lobbying and ethics reforms passed in January are too strong.  He was one of only two senators who voted against it.  And if the House passes it, he claims he won't run for re-election in 2010:

"If this becomes law, I will guarantee you I won't run again....I will promise you, very few people in the future will run for Senate or Congress because every campaign will be about somebody making a complaint."

Sen. Coburn expressed concern that if a senator committed an "accidental mistake" it could cost up to $500,000 in legal fees. While we are not sure where this figure comes from, we are more curious what type of "accidental mistakes" Sen. Coburn is afraid he may make. Is he afraid he might be an accidental tourist in Scotland, perhaps?