Running Around In a Sleeveless T-Shirt With Flesh Eating Zombies Around?

I know it's a comedy, but come on!!! You also have the other guy brilliantly punching a zombie in the mouth with a bare fist(!!??) I know Ken Foree also did this in 'Dawn of the Dead', but wouldn't it be very, VERY risky given that you could very easily cut your hand on the zombie's mouth and end up a zombie yourself??? There is also a scene where the older man who is with Steph gets bitten on the arm VERY HARD by the disfigured zombie inside the office building, but a moment later he's talking to her and he shows no signs whatsoever of being in any kind of pain(!!???) He never makes a facial expression indicating he is hurt, nor makes any reference to it all(!!??) He seems totally fine as if it never happened! It seems to be a combination of a bad actor, a bad director and a total lack of continuity! Again, I know someone will respond saying something stupid like "Chill dude, it's just a movie", but really it is just sloppy work!