Blizzard have commented on the recent suspensions due to lack of participation/AFKing in battlegrounds in Wrath of the Lich King Classic, talking about how these suspensions are triggered, including mentions of some erroneous bans, as well as shortened ones.

Non-participation (Source)

I wanted to take a minute to comment on the recent action, and clarify our policies a bit.

We recently discovered a bug in our analytics data that called into question some of these suspensions, and in those cases we will reverse the suspension. Some others were so egregious that we’re still confident in the lack of participation, and those actions will remain in effect, though some will have reduced penalty duration if it was a first-offense.

On the larger point about how these suspensions are triggered, we have data analysts poring over a variety of metrics that we collect, to look for a lack of participation. There is no single metric that gives a clear picture, so we look at a variety of metrics to make sure we allow a variety of valid play styles. “AFK” reports from other players are just one of these metrics. We certainly look at them, and they can be a good clue for validating our other metrics, but we do NOT issue suspensions based solely on these reports.

When lots of players report a player AFK in Alterac Valley, the only automatic behavior is the application of a debuff that prevents you from gaining honor until you engage in PvP combat, which can be seen in-game.

We do periodically review the metrics we use for determining whether somebody is participating or not, and we are conducting one of these reviews right now as we look forward to new battlegrounds being introduced with Wrath of the Lich King Classic. Our review is not limited to the new battlegrounds, but they provide a good opportunity to make sure we’re looking at the right criteria. I don’t want to list all the criteria we look at, because doing so would help bad actors avoid detection, but it is absolutely more than afk-reports.

I can’t comment on your specific case, of course, but thank you for appealing it through the normal channels!