Well, for one thing, lions run upwards of 400 to 500lbs, vs. a jaguar that is 100+. The tigers that were recorded in the Man-eaters of Kumoan, were equally as large. A broken fang doesn't necessarily mean that it was in pain, but it did hamper them from killing prey in the 300 to 400lbs range. Also, jumping over high fences with 100+ pound human was not a big act of strength for them.
As Mike said, it doesn't mean that healthy lions cannot develop a liking for humans, for all the reasons he mentioned, but these are powerful creatures. However, most of the evidence from the carcasses pointed to broken teeth of a broken limb or deformity of some sort.
Interesting discussion though.