I did not suggest they were going to abandon Satoshi's security model. I explicitly stated they are not. Period.
Ah okay, misunderstood.
I believe Maxwell is referring to the inability of the segregated witness to construct a proof-of-cheating. And the implication is if you didn't do this historically, then you can't soft fork to add the segregated witness feature. But I didn't read Maxwell's comments, so I am just extrapolating based on the quick read of the one epistle fro Wuille I linked to.
His comments were linked above on this thread. Here's the link again:
https://www.reddit.com/r/Bitcoin/comments/3vq8hm/multiple_new_bip_proposals_coming_up_on_day_2_of/cxpxi5t"uh. not having the commitment results in serious vulnerabilities, I would .. uh. suggest they add them ASAP ... "