Well, if you buy into the notion that playcalling wasn't to blame, that the Oline was the main issue, then it will still be on Jason to fix that.
If we go once again not really fixing the line, just throwing a few JAGS or a mid-level draft pick at it and crossing his fingers hoping for the best, then he deserves as much blame as bad playcalling.
Jason has had years to try and convince Jerry to throw real resources at the O-line. He HAS gotten Tyron to be fair, but that's it. One answer to a five part problem does not a solution make.
I understand trying to sway Jerry from the shiny toys to go get needed linemen is probably very hard, but it's something a HC HAS to do to be effective. If he can't do it, especially this offseason when his job is on the line, he will never be able to.
Here's hoping Garrett has it in him this year, even though with the switch to 4-3, Jerry will probably be poo-pooing the notion that a few good O-linemen are needed and a high (1st preferably but at least a 2nd) draft pick must be spent. If not, what little hope I have Garrett might be able to recover and become a decent HC will fly away.