It's somewhat common in young/juveniles to see false egg spots in males - it's a way to "fool" adults in thinking they are females as a way of protection. You tend to see it more in plakat juveniles, but it can easily happen in the long finned variety too.
Doesn't happen a lot, but it does happen.. I have never heard of it being a "defect caused by inbreeding", this is something they do for protection.. it's not a deformity. I also have never heard of the IBC disqualifying for that..
It also makes no difference whether or not the fish is a pet store fish... every fish comes from a breeder, whether you buy it at a store or from a person, every one comes from a breeder.
These are natural, common enough form of protection.. nothing wrong with having them, they don't affect the health/well being of the fish in any way and most tend to outgrow them down the road.