It's not uncommon to see broken feet - the human foot has 26 bones, with joints everywhere. These joints are more akin to two surfaces being "glued" together than "held" together by the more rope-like ligamentous network in the knee, for instance.
This season in the NFL, we've seen quite a number of Lisfranc injuries, which is essentially a fracture or sprain of the midfoot (where the long bones of your forefoot meet the network of bones just past your ankle) caused by stress to a free-floating heel while the toes are planted.
What happened to McCollum is probably different, from what I could glean.If you take a look at the video again, there is no real obvious moment. You don't see a player getting his planted ankle rolled up under someone else, there's no jump followed by a gut-wrenching twist, anything like that.
What did happen? Well, I went back to the video of the injury and went frame by frame and here is my best guess: right around the 0:18 mark, C.J. drives down the right side of the lane and plants to stop with his right foot while he passes the ball out to his teammate Anthony D'Orazio on the wing.
It is likely this quick plant by McCollum that led to the injury. Had we seen an image where McCollum's foot planted and stopped but the rest of his momentum kept moving to the right, it would have resulted in that typical "ugh" - inducing high-ankle sprain that we see so often out on the basketball court.
McCollum instead had a definitive plant and stop, which likely means a high level of force driven down into his foot, resulting in whatever fracture(s) took place. This is, in some ways, a good thing. While bone does take a good bit longer to heal than a ligamentous injury associated with a sprain, the likelihood of a re-injury is a bit less.
Obviously an injury means that, going forward, McCollum's foot will never be more than 99% healthy again, no matter what parts were injured. However, the kind of cutting, planting, and direction changes inherent to his role as a point guard are much more likely to re-injure a bad sprain (and weak ligaments) than a break, especially the notoriously pesky and slow-to-heal high ankle sprain.
So is eight weeks realistic? I think so. It generally takes about six weeks for bone to heal, at which point C.J. can return to more full physical activity and eventually the court. Now, if he were to return in exactly eight weeks, that would put him on the court right on time for the Mountain Hawks' regular season finale against Navy, and there is no reason to expect anything different just yet.
It may take him the duration of the Patriot league conference tournament to return to the level of play that we are accustomed to, but C.J. should be fully healed from this unexpected injury just in time to help his team succeed in whichever post-season tournament they are able to reach in his absence.