My opponent completed his Druid Sidequest with a Dire Wolf Alpha on board, and that minion did not appear to gain attack. I don’t know if this was just visual or a real bug, as I attacked the wolf first.
https://imgur.com/gallery/kOm8uZq
Seen on Android Phone (Galaxy S8)
When you killed the Dire Wolf, do you remember whether the Mad Bomber’s attack reduced to two? If the attack had also been reduced for some reason (can’t think of a way to do that to a card in deck at the moment), and then boosted back by one to its original value, to would still show up in white (it is also printed white when it is below the original value).
The Mad Bomber’s attack remained 3 when the Dire Wolf was killed