Do you mind sharing where you're getting your numbers? Almost everything I've seen has him at $13MM this year.
Anyway, I still think it was a bad contract. $3MM originally guaranteed, heavily bonus/incentive laden. He missed out on $3MM last year (should have been $4MM, but it appears the 9ers are throwing him a bone for not hitting 90% of defensive snaps both last year and this year), and it required him to meet all incentives to hit $13MM this year. Luckily for him, his base salary will raise next year, but he's still going to be out of the top 5 paid CBs (and likely further down after this offseason's signings).
Sherm will claim that he bet on himself and he "won" that bet, and while he did hit his incentives to make good money, I'm not sure that he "won." An agent could have (a BIG COULD HAVE, cause we'll never know) got him more guaranteed money, could have been structured differently, etc. He campaigns against using agents when an agent gets at most 3% of a salary... he lost more money last year than an agent would have made off his entire contract. Then you look forward and see the contract will only escalate by $1-2MM... Just my opinion, but I think it was a bad contract.