A 16-year-old boy was killed in my grandmother’s area (western India) about thirty years ago by a mugger crocodile that was only six feet long. It took his arm off above the elbow and he bled to death.
Contrary to popular imaginings, crocodilian teeth are more conical and stout than knife or razor like. They are extremely strong, and are deeply rooted in a heavy jaw bone. This makes them well suited to holding prey fast and preventing its escape, but not so much for disassembling it. The idea that one might bite off a finger, hand, or limb is unfounded, if by “bite off” we mean something shark-like.
**Colibri **and **RNATB **describe typical crocodilian feeding behavior when dealing with large prey. Grab on with those powerful jaws, then spin until something tears off. In other words, the “death roll”, although those words are better suited to overblown journalistic accounts than as accurate description. Death of the prey may indeed occur as a result. But death may already have occurred some time in the past. Even then, a crocodilian would need to perform the “death roll” again to remove additional swallow-sized chunks from the carcass. A number of repetitions might be needed, depending on the respective sizes of the crocodilian and the prey animal.
The previously mentioned American Crocodile and the Aussie Fresh Water Crocodile typically consume fish, which are mostly of already-swallowable size. “Death rolls” are not needed in their feeding activities.
I’ve heard on the Discovery Channel and the like that crocodiles also have all kinds of nasties in their mouths, to the extent that nearly all crocodile bites need to be treated and watched carefully lest they turn septic due to the bacteria. Not sure of this factoid’s veracity, though.
So even if they don’t kill you directly, infection afterward might.
Bacteria, including potentially pathogenic bacteria, are certainly present in the mouths of crocodilians, as they are in the mouths of most animals. Mouths, like all parts of the gastrointestinal tract, are effectively “outside” the body and walled off from the body by specialized tissues, secretions, and other active defenses. Thus really nasty stuff may be carried around in the mouth that would be life threatening to the host if allowed to be actually “inside” the body.
Crocodilian diets may include shall we say “less than fresh” items, and they don’t brush after meals. This contributes to the growth of bacterial colonies. Given the length of their teeth, it follows that bites may deeply introduce those bacteria into a wound. So yes, indeed, infection could be a problem if you are the victim of a crocodilian bite.
Assuming of course that you survive the initial attack.
Crocks often deal with not being able to really bite off chunks by stashing their lager prey under water until it bloats/softens/rots enough to easily fall apart via violent shaking/spinning.
This also makes them more dangerous, as they need to plan ahead, so they take prey whenever possible, not just when they are hungry.
They kill beers? 
Unless you are another crocodile - which is often the case, given they can be so aggressive to each other. They have an amazing immune system, possibly the most efficient in any animal. Given what they eat, where they live and how much they chomp at each other, the fact they don’t tend to get infections is rather good news. One crocodile farmer I visited showed me an old croc who had lost half his jaw in a fight with his neighbor. The farmers hadn’t even known the croc had been injured, he recovered so fast. The antibacterial properties of crocodilian blood is being studied for products for human medicine. Incredible creatures.
[cajun man voice] Dem crocks’ll kill any damn ting! [/cmv]