FYI: Wild Severums are notorius for having parasites embedded in their flesh. What's surprising in your description is that these "bumps" are getting smaller. Usually, when a parasite comes to the surface of the flesh, it bursts through to escape the host to breed. You'll see a red area that you treat with an antibiotic and everything goes back to normal. The fact that they were fuzzy leads me to think that he may have actually injured the area and a small fungus ball developed. If the fish is healthy enough, it should all go away with you doing nothing.
IF the fuzzy ball was grey (not white) in color, it could be the virus Lymphocystus. Once again, wild severums often carry the virus. Physically removing the fuzz ball helps control the spread of the virus but don't be surprised if other fuzzys pop up. This would be a sign that your tank isn't as clean as it should be.
Hope this helps...