The .223 is certainly on par in terms of size with a .22..
But you need to deliver one helluva lot of energy to the target to make a hole the size of a coffee cup. Much more than a .22 will deliver. The .22 can be quite lethal (don't get me wrong)... but it won't make a hole the size of a coffee cup. It's lethality depends on the round traveling in different directions inside the body through a relatively small clean entry wound (owing to it's low velocity)
Either the wound size observation, or the suggestion that the round was a .22... is wrong.