Yes sanct didn't hit MA first but anyone with two braincells would know that MA would respond to sanct doing that just around the time MA gets notice from Sancts ally Havoc.
Yes both MA and Sanct are obviously in double hostiles, I don't think anyone is denying that. But the difference is that Sanct would not be in a double hostile if they had not decided to pull a dickish move on MA, they knew they would be getting a response.
It's like going into a Hells Angels biker bar and loudly exclaim, "what sort of leather gay place is this?" You won't be getting out of there in a good shape unless you're Chuck Norris.