He lied about his involvement and got away with it
What key involvement do you think he had? Nixon was President and had the political power. Mitchell controlled the money at CREEP and dictated how it was going to be used. Liddy and Hunt actually organized the break-in. What's left to lay at Dean's door?
I despise Nixon the most because he had the responsibility, the authority, and the power to put ethical people into the administration to uphold the oath he took. I think he failed miserably at this and then compounded the problem by obstructing justice.
Likewise, Mitchell had the responsibility, the authority, and the power to see that the laws of the United States were upheld. Instead he organized a criminal organization financed with laundered money. I forget whether he was one of those convicted of perjury. I expect much more from the Attorney General of the US.
And what can one say about people like Liddy and Hunt? They have no bounds on the means they will use to achieve the ends they justify.
If Dean understated his culpability, what did he conceal? What crime of omission or commision most stands out that makes you despise Dean?