Coulda, Woulda, Shoulda

"Dandy" Don Meredith probably would not think the error in this USA Today article about NFL announcers is fine and dandy. I'll give you three chances to find it. If you can't, it's time to punt.

The mistake is, obviously, with "would been seen." The writer simply omitted the word have between would and been. No big deal. But it does allow me to bring up the "would have" issue.

When used to express probability or presumption, "would have" is correct, as is its contractive form, would've. What is not correct is "would of." Why do I see this so often? I'm sensing it's because the contraction would've sounds like "would of." Any other theories?