When Glenn and Nicholas are falling from the dumpster, their heads are falling away from it (feet towards it). Glenn is then shown on the ground with his head toward the dumpster.
Supposedly, the Alexandrians had looted the nearby town with the pet store. The first scenes of the Alexandrians showed they had dogs, but there is still a lot of dog food and supplies in the store.
No matter what the Alexandrians do, they are contradicted. When Heath says not to leave anyone behind, Michonne tells him that sometimes they have to because there is no other choice. Even though the Alexandrians were still able go out and build more than Rick's group ever did at the prison, they have been treated badly for sometimes leaving others and being cautious.
Despite the experience of Rick's group (simply poking walkers through fences before), they scattered from the prison knowing others may still be fighting or hiding somewhere within. Half even neglected to follow a road they knew a bus load of companions had gone. It isn't clear if Rick's group (or writers) are aware of their actual behavior, hypocrisy, and failings or not.
Before they get in the pet store, there are few enough walkers down each street for Michonne to kill just by herself. She has easily done this before surrounded by more than a dozen.
Trapped in the pet store, it's as if everything with Michonne using "pet" walkers to move among them has been erased from her mind. She should have immediately thought about that trick she had used for a very long time.
After the pet store, Michonne is in front of the group (where there are no walkers) instead of fighting the walkers or even help drag the injured.
Then, at the fence, Michonne acts scared and horrified as if this is the first time seeing anyone attacked by walkers. Seeing him slowly being torn apart, she doesn't even put him out of his misery.
Trapped in the pet store, it's as if everything with Michonne using "pet" walkers to move among them has been erased from her mind. She should have immediately thought about that trick she had used for a very long time.
After the pet store, Michonne is in front of the group (where there are no walkers) instead of fighting the walkers or even help drag the injured.
Then, at the fence, Michonne acts scared and horrified as if this is the first time seeing anyone attacked by walkers. Seeing him slowly being torn apart, she doesn't even put him out of his misery.
Glenn is supposed to be an experienced survivor who is much more competent than the Alexandrians, and he is even given a leadership position. However, his actions show less savvy than when he was first introduced: Still oblivious to his blunders at the warehouse, once again Glenn isn't carrying much ammo or anything to poke and slash the walkers attacking him and Nicholas. In addition, when Glenn and Nicholas are running to the dumpster, a fence clear of walkers and a fire escape are seen. Either could have been climbed to escape the walkers.