They fired this guy at work i was close to because he made 1 mistake that was super minor and now theyve got this extremely lazy fucker in here

He sleeps the entire shift, refuses to do patrols or fill out reports, and disappears during the shift for hours at a time. Ive told my boss about this and he keeps saying something will be done but its been a month of this guy doing nothing. I have pictures and videos of him on my phone sleeping, and electronic logs of him missing for hours along with camera footage of him being gone.

Is this normal behavior thats to be expected at work? Am i secretly the hardest worker on earth? They fired 2 people for much less than this, one of them was really good at this job and was never late or called off. This lazy fucker was late by an hour today and has been late almost 3 days a week since he started here

I would expect to be fired immediately if i was doing this shit. Is it common for people to not di their job and not get fired or disciplined?