I'm certainly not going to be an apologist for Johnny Jolly not avoiding repeat punishments from the NFL for conduct- he had clear direction to stop doing certain things, and stop being certain places, and he broke all those guidelines.
The one thing that I do think is worth thinking about here is that he was convicted around possession of purple drank (snicker all you want). The problem with this is that the law treated this as a huge amount of codeine, and worthy of being looked at as grounds for trafficking, which is a whole other mess apart from simple possession. The law in Texas doesn't necessarily provide language to deal with new(er) narcotics, and uses existing language to hammer people when the punishment may not be the best fit for the crime.
In terms of whether he should get a shot or not, the Packers haven't jettisoned his rights during his suspension. I think often about TT's treatment of Koren Robinson, who he brought in from Seattle as a FA despite a really tough time with alcohol and related charges/issues. Robinson used the opportunity provided to make real changes in his life and he was a stand up player for us while he was in uniform. He certainly wasn't a lasting solution, but he gave us quality reps at a price that was doable.
As a GM, that's what you're looking for- value. If JJ can come in, show that physically he's ready to play football, he's worth the vet minimum to see if he can make the team. It's not like we're swimming in fantastic depth at DE, and frankly, before he got nailed the last time, he was batting down passes with regularity and played effectively in our base package despite not having Chris Canty prototypical measurements.
Whether he makes the team really depends on whether or not he can prove he's one of the 6-7 best options we have along the DL. That's a tall order, but he's really 27 in terms of number of reps on the tires, much like Ricky Williams played younger that his age at RB because of the year or two he was "retired." He ran effectively well past 30, and most attribute that in part to the number of reps he didn't accumulate in those off years.
Interesting stuff though. As much as I like the draft and develop, I think if you can get good quality reps at a real value price out of some vets until you can find that draft pick that represents a real upgrade in terms of on field execution and performance, I never forget how much the Patriots improved by signing a ton of little regarded FA's on their first SB run. Savvy signings like that seem a lost art, and I'm surprised that TT hasn't found a way to make better use of them.