Well I was there with Fisu when that happened, so was thEnd. I checked the logs and this guy was swearing his arse off. I'd have personally ban him myself if Fisu did not do so.
The issue here is that there is no establish precedent as to the minimum or maximum punishment for flamers. Flaming covers a very wide scope and imposing one universal punishment for all flamers would not be adequate because each case is subjected to its own facts.
For example: When a player calls another player a noob or a cheater, that is flaming. So is the case when a player swears at someone's family or making racial slurs.
Albeit both fall under the same category of offense, the weight of each misconduct is significantly different and it is only fair that a heavier punishment is imposed on the more serious case. This is where we admins come into the picture, what punishment suit the offender should fall under the discretion of the admin. Though it is important also to note that different admin has different standard, so long as we(admins) do not exercise our authorities outside the scope of our limitations, it should be fine.
Looking at Fisu's perspective I can understand why he did what he did. The seriousness of the offense committed by Roby calls for a heavier sanction. Fisu later on explained to thEnd and me that he gave a permanent ban because he felt that it was adequate, and if it isn't, the player can always make an appeal for unban (which he did) wherein thereafter his case will be heard by the bulk of the community & the highstaffs.