Yeah, it's just because he hasn't died. Gold from assists and csing increases bounty. And dying is the only way it goes down. Difference in gold between individual players has absolutely no bearing.
In the old system, the team that's behind in gold would have their bounties reduced. For some reason, the rework changed that to happen only when objective bounties are active.
The old system did not have bounty suppression at all. The new one does. The tuning has just been very mild. The rest of this post is accurate.