Rick's final episode begins after a cliffhanger from the previous instalment: Rick, impaled on a rebar, is bleeding out while thousands of zombies are descending on him from two sides. It's a chilling closer, leaving the hero mortally wounded and in a pretty precarious situation, but gosh darn is it dumb.
Having Rick being wounded was necessary to ramp up the tension and really make fans think he was going to die, but the way it happens is so random. After an episode that's not focused on him, the Deputy Sheriff jumps on a horse to divert a walker horde away from the bridge he's been hellbent on building. Leading one pack of zombies into another though, his stallion gets spooked, and it bucks him off onto an inconveniently placed bit of rubble.
The randomness is actually brilliant at selling the danger of this world - and the wound itself provides a nice bit of symmetry to Rick's gunshot in the pilot - but the way it's shot, and how out of nowhere it is, is incredibly awkward.
It's not technically part of the episode, but because it drives everything that happened next, it was worth mentioning.