If you reported this player post-game, then you did all you need to do. The boards are not the place to report other players and is in fact against the rules.
Something to keep in mind is that not every offense will always result in an immediate punishment, which is why, if you look around the Player Behavior boards, many people will post chat logs from multiple games. This does not mean that this player's behavior was acceptable in that game, just that it wasn't quite enough to push them into punishment territory. Your report against them is still valid and will help get them punished if they continue that type of behavior in the future.