a month is nothing. i'm sorry, but you can't really even be sure that a fish is well enough to come out of quarantine until after 2 weeks. a month is simply not enough time to ascertain anything beyond a fish's relative health.
let us know when it's been 6 months with no incidents and then there'll be enough information for a discussion.
--off-topic--
is it really that important to determine whether or not its a bug? i'm not positive that's the focal point of the picture anyways.