At the end of the film when Katya is running through a parking lot to escape the zombies, a car can be seen driving down a street in the background slowly and casually as if circumstances were normal.
Two characters make a weapon out of a floor scrubbing machine and nails. They use it on the midsections of the zombies they encounter. This incapacitates the group. The only way to stop a zombie, and the movie also says this, is to inflict severe damage to the brain. Some of the zombies even seem to be dead from this attack.
One zombie gets knocked out by a roundhouse punch, but as as soon as the characters are far enough away it gets back up and gives chase. Zombies do not suffer knock outs.