There are several fascinating themes in "Dorylus," pushing the season ahead in an exciting way, and then there are several not-so-fascinating themes which are actually confusing. I like where this season is going and the good outweighed the bad in this episode, but there were some very questionable decisions on the writers' part.
I'll start with the positive, the 6-5 vote on working for the cartel. This issue looks like it will divide the club, not just in the short-run but also the long-run. On the one hand, there is Clay, who convinces Bobby by offering him the leadership of the club and explaining that Jax wants to leave. On the other, there is Jax, who convinces Bobby by agreeing to head the club without him. The immediate consequences will be a bunch of unhappy people working a dangerous job with the cartel, but there will be lasting effects from these lies and half-truths. Clay's behavior in the episode is especially troubling--smothering the already-dying Russian, getting physical with Gemma, and threatening to kill Piney--and gives us good reason why things will fall apart sooner than later.
We don't learn much more about JT or how Gemma was involved, but Gemma confronts Tara about it, telling her that digging further will bring up too many old wounds. Although the way she acted was convincing (because Katey Sagel is great), I don't think she's genuine. In any case, Tara doesn't really believe her and hides the file in a box in the garage.
The other parts of the episode I didn't like so much. What's up with Roosevelt talking to Juice about Juice's black father? SAMCRO might not be angels, but they're not like the KKK or anything. The other plot with the stolen guns was weird in that it didn't feel like Sons at all. A couple of street punks actually steal the truck from Kozik, which was stupid by Kozik and predictable. And the plot doesn't go anywhere either. The guys meet Cool Black Mama who disciplines her sons whom the guns were sold to and are off on their merry way.