Banshee Bob remains a mystery.
As we all know, there is no medal or elite light vehicle kill for a Banshee Bob. (And now that stats are on halo.xbox.com, no medals for any Bob, and Bob doesn't show up in the enemy list either ... but I digress.) We can confirm that Banshee Bobs are "Gold Ranger-class Elites" because killing them springs the "If it bleeds" and "Golden Opportunity" daily challenges, when they are in play.
So today I went Bob hunting on New Alexandria to fulfill the "If it bleeds" daily challenge. I decided I would follow Kat's instructions and play it through as directed, squatting for Bob only when the game play brought me close to the spawn point. Not a focused strategy but I was having fun. I didn't get Bob when I was called to the night club, and just continued with the mission. When I was called to Nakomi(?) tower, where the bugger trap is, I cleaned up the grunts and brutes in the front foyer with the Falcon's gun, and briefly pulled out to down two encroaching banshees. One of them tripped the "If it bleeds" challenge! I was stunned, as I could swear neither banshee was boosting, which was verified in Theater mode. This was near the end of the mission around the 28 minute mark. I finished the mission and replayed it in Theater mode. I traced back both banshees to their spawn points and both came from out of bounds. That is, neither spawned where Banshee Bob spawns. I also squatted, in theater mode, at Bob's spawn point, and he never showed. (Yes, all 30 minutes of the mission. I know, one would think I should have better things to do.)
I can post the mission, but I doubt anyone would be interested, since theater mode doesn't show the daily challenge popup. That is, you have only my word that that's what happened.
I guess then my question is, has anyone else experienced a successful daily challenge, seemingly at random, like the one described above?