Earlier quoted context omitted.
A Macaque, maybe 15 kg in weight, has the aggression claws and muscle to take on any non-beefy human and win, not doubt about that.
Male macaques also have very large canines, and massive jaw muscles to use them. A bite that severs a major blood vessel could end very badly. They also move a lot more...three-dimensionally than you might imagine, making it hard to predict where they're going.
Macaques have large teeth and strong jaw muscles (as do dogs); but unlike dogs (or say even piranhas), it doesn't look like monkeys rip and tear flesh like canids. Their mouths are a lot like human mouths: incisors in the front, two canines on either side, and a bunch of (pre)molars, indicative of omnivores. The two canines will definitely pierce the skin. The incisors, most likely as well; but the molars are absolutely useless here.
Whereas dogs (and more specifically sharks) have "saw-like" teeth, that combined with strong neck muscles (and a propensity to grab hold, and shake vigorously, as if they're literally sawing away flesh), make them a lot more lethal to most land mammals.
If we include monkey eating habits, I don't see any large mammals on the list (all the mammals they may eat are smaller than them); compare that to the canid family, that will hunt down mammals many times larger than them. I just don't see how the monkey is built to be able to kill a human being.
Granted, it's going to hurt a lot to get bitten by a monkey. But I just don't see how a 40lb mammal can do that much damage. If you can somehow restrain it by the neck, it's basically over for any mammal of that size without claws (or another means of escape) -- which monkeys don't seem to have.
Now, if we're talking a chimpanzee? I'm going to do everything in my power to get out of that situation. But a monkey? A large dog is more of a threat.