Not true, a blue already adressed this.
While I understand the frustration, I think it is a huge mistake to assume that Scarab Lord was ever a garauntee on a PVP server. The quest-chain is long, and anything can happen that can prevent you from getting the mount. There’s a reason that few people ever even get it.
I think there’s also room for debate on the idea of personal server choice. Those players decided to roll on a high pop server, which means that sometimes, during widescale events like this, the servers are just going to go down. It’s comparable to a ddos. However, I still think your complaints about faulty servers are valid, but only to a certain extent. I think it would be fair to restart the war, maybe?
The issue here is proving intent. Swifty got banned for crashing servers, on the exact same premise. So it is actionable, but it is also reasonable for horde to be there for other reasons besides “lagging out” the server. Such as, WPVP, just watching the spectacle, claiming their own scarab lords, etc.