Are the GM really reading my ticket? I'm just wondering....

So I was doing the SM quest, and on the blood infusion, I had blood mirror before getting bit, and I bitted three times, but I didn't get the quest to finish, and still died to gushing wounds.
Made a ticket explaining the situation to see if there was something bugged, or maybe my toon was bugged, but this was what i got back.
https://i.imgur.com/Twrh8GC.png

Note: GM said "Make sure you are not in a raid group when trying to complete it"..... Really? REALLY?!! This is the SM quest we're talking about, how do i even turn it in without being in ICC raid....

Not that I have anything against the staff, but this response just .... I have no words.

Anyways, back to the topic, does anyone know what could have went wrong with what i did? I mean I did everything in order according to both online guides and the quest details.

Any help would be appreciated, thanks!

1. be sure yo have shadow's edge equipped all the time (even when you have the Off tank link (blood mirror)
2. Once you had off tank link (blood mirror) for enough time you gain a new debuff ( I do not rember the name, but it is a specific debuff you gain thanks to the quest)
3. Now you can stop doing off tank and start doing Bites phase