I didn't watch the game or any other games of the tournament. But I've seen screenshots of it, and from the looks of it, he doesn't seem to happy about it. In fact, he seems VERY unhappy about it. So to me it looks like he hadn't asked them to send him messages.
With that said, I think the DH crew could've gone either way with their ruling regarding replaying/not replaying/give a game loss for that game. If he didn't at any point after recieving the info play around Hunter's Mark or the Bow ehere he normally wouldn't, I think it's kind of silly to make him lose the game or even replay it, since it would't really affect the outcome. And if that was the case, I think the DH crew made the right decision.
In the end, though, I think the real blame lies in Blizzard. Not being able to turn off the chat in a game that requires online play is not very tournament oriented. And they've held their own tournament. Which I can't imagine wasn't live streamed as well.
Finally, as a side note, I think it's also kind of weird that some random guy could cause a guy to not win $5000 by being a jerk. In a 1v1 competition, there should be no outside influences. And if there is, it's the guy who is outside and influencing that should be dealt with, not the guy who is being influenced. If he's the one responsible, it's cheating, though.