You are putting too much pressure on the safeties IMO. Their job is to help the corners when possible. Not completely bail them out. Otherwise, what exactly is the point of Kareem being out there?
The safeties were not good, but when you have lbs that struggle in coverage and corners that can't stay within tackling distance of their man it makes your job harder.
I also presented the safeties in these plays as they were.
I look at what their job assignments were and whether they were able to fullfill them.
On the R. Williams play, for example.
It was a one-receiver route with Wilson lining up on that side.
If a safety cannot provide any form of help in that instance, thre's no other conclusion that can be drawn other than he failed utterly at his job.
On the Jabar Gafney 50yd catch (which was actually on a different thread), the Texans were in cover 2 (5-underneath zone, not man).
There was only one receiver on that side and he (Gaffney) ran a skinny post right toward Nolan's landmark.
Nolan bit on the run fake and vacated his zone.
Jackson stretched his zone more than 30 yards and ran after the receiver.
But in an underneath zone, you can ask the CB to stretch only so much.
(I can show you a Dunta play I happen to found to show you how much further away from the receiver Dunta was.)
The mistake was unequivocally Nolan's.
It had nothing to do with Jackson's speed.
In a 5 underneath - 2 deep zone, the CB seeks his landmark, looks for the QB, and reacts.
It's not Jackson's fault that Nolan failed to keep his assignment.
But because Jackson ran after the receiver that he was blamed for the play.
(If only you remember who posted a link to that video in the first place, you would know that he's one of the harshest critics of Jackson, and he was completely bias there.)