Issues with this movie....Spoilers
Where to start? This movie is so full of things to criticize.
Tyler arrives and is almost immediately attacked by a zombie. After escaping, he does what anyone would do - leave his nice shiny truck and run off into the woods alone.
As others have mentioned, this mysterious agent acts very fast, Mack become a zombie almost immediately after being bitten on the arm. But even so, it would take a bit longer than a few days for a bunch of self-reliant loggers to go wacko this way. They're used to being on their own, they have firearms and lots and lots of logging equipment, aka chainsaws. Yet they're rarely used and not at all when their camp gets overrun.
The first time they try to escape, they are stymied by a padlocked gate. Uh, you do have hammers, crowbars, chainsaws and presumably at least a few explosives. Yet they turned back without even denting the gate. At least ram it once with the truck and see what happens!
The second time time they're thwarted is by a pile of logs across the road. Okay, I'm sorry, but I feel pretty strongly that loggers would know what to do in this situation. Logs across the road, oh no, what will we do? Turn back! Idiotic.
There were a total of maybe two dozen zombies loose at the most. Would you really run off and leave 4 behind you when you could turn and finish them off one at a time? The zombies are not exactly sympathetic creatures so it's hard to believe that the survivors would be so reluctant to crush them with a club or rock. Yet they are too soft-hearted for the most part to finish the job, even Tyler who doesn't know any of them. You'd think at least they'd divide up so the loggers would kill the enviro-zombies and the greens kill the logger-zombies, no love lost there under any circumstance.
Clearly the filmmakers are unfamiliar with the concept of a CEO. He gets backed down by an underling who merely threatens to make the board vote to 'clean up' the mess, presumably by killing the CEO's son. So we're left with an idiotic ending where the CEO is sad that his kid is now dead, rather than him acting like a CEO and kicking some butt to get things done his way. <sigh>
And Carter. What a strange character. Finally he runs away, intentionally letting the zombies into the camp. And the zombies don't sniff him out, they walk right past him for food. No guard posted? I think if I was surrounded by company men who wanted to kill me to hush things up and zombies who wanted to eat me, I'd post at least one guard. And I'd certainly have locked up that ultra-dodgy acting Carter. There was one surprise - I was sure Carter would panic and kill Tyler with his axe when he came to rescue him. Instead they both just got bitten.
By the way, after Carter refused to let him into the shelter at first and then acted so cowardly and complicit all the way thru, why was Tyler so keen to risk his life to save him? He hadn't seemed at all heroic earlier and most guys would probably choose to stay and protect their new girlfriend instead of the creepy guy named Carter.
Strangely, by the end there seem to be far more zombies than could be accounted for by adding together two logging camps and the group of environmentalist. Did they happen across a group of campers? If so, why are there no 'little' zombies. These zombies seemed to be pathetically weak and easy to take out, yet very few of them were ever eliminated. Trust me, if someone ever faces zombies I don't think they'll be content to just push them aside so they can pass, leaving them at their backs.
The one good thing about this movie is that it's amusing to watch with friends so you can take turns mocking it and picking it apart. I'm not sure that's what the makers intended, but it does deserve a star for that fact.