Okay, we kind of have a nice Shield watching club here. Allow me to get my rant on.
Co-Pilot is an episode from the latter half of season 2 that takes us from the then-current point of The Shield's timeline back 14 months. Ideally, such an episode can be pretty good. The show has been going on for more than a season and a half, it's hot stuff, why not take a peek to just before the beginning of the series? Note that TV logic tells us that "14 months ago" would be *just before* the series starts. Our brains tell us that in most shows, 1 season equals 1 year, and there is no reason to make us believe otherwise with The Shield. And that's where the problems come from.
Co-Pilot brings us back to just before season 1 starts. Looking back on season 1, episode 1, we are given a very clear impression that The Farm has been going on for a while. There are fairly deep character interactions, and of course Mackey's Strike Team is fully in place, totally corrupt, and the whole force seems very buddy-buddy. Also in that very first episode, it appears that Acevada and Julien have just joined the project--they are newcomers in something that has apparently been working as a machine for a while.
Well, flush those things the pilot told you down the toilet, because Co-Pilot is here to rewrite history! Co-Pilot tells us that the beginning of the series roughly coincides with the formation of The Farm and Mackey's Strike Team. So we are lead to believe that Mackey's web of drug-dealing corruption, and the camaderie and trust that has formed amongst his Strike Team, has formed extremely quickly over the few weeks before Co-Pilot and the pilot? How is that possible? How could Mackey get his drug and corruption game, make friends with all of his new team members, people that share in his corrupt games, in the space of a few weeks? In the pilot, we are lead to believe that Strike Team is something that has been around for quite some time; a gang of bullies that is allowed to run rough because they've been around for a while, or grandfathered into the Acevada era. . .but no, Strike Team wasn't even formed until Acevada took over, er, started, The Farm.
In the pilot, Acevada is extremely suspicious of Mackey and Strike Team, again, as if they were a program that is from an administration previous to his, but this is not the case. Not only was Strike Team formed just as Acevada took over, but he probably could have prevented Mackey from ever being on the team. Acevada, in effect, gave the job to the rogue cop who he's trying to take down just a few weeks later when the pilot hits. None of this makes sense! Why would Acevada let someone get hired for a prestigious position when he is not 100% sure? When he has political ambitions and wants to look good? Heck, he hires his old buddy to infiltrate Strike Team in the VERY SAME EPISODE!
Moving past that enormous and troubling story hole that pretty much makes season 1 incomprehensible, there's the Julien issue. In the pilot, it basically seems like it's his first day on the job, but again, he's right there in C0-Pilot, joining the team at the same time as everyone else. Why a total rookie would be picked for an experimental police unit I have no idea. But the Julien thing is what 100% guarantees that the first episode of the series happens very shortly after the events of Co-Pilot. If Co-Pilot took place months before the pilot, Julien wouldn't be referred to as a rookie in the very first episode. So Co-Pilot, at most, takes place a handful of weeks before the pilot, which proves that all the Acevada/Strike Team/Mackey stuff mentioned above is legitimately a serious plot problem.
Basically, Co-Pilot is a major, major black eye on the series, and it took me a few episodes to forgive it. I can't believe this got past the showrunner and producers. Not only does it introduce serious plot issues, but it's also a total filler episode. It's trying to be clever, and in doing so, it makes the back story BAD. For any of the Shield watchers still behind me, skip this turd. It adds nothing, and it will put you off the show a bit. A total disaster.