I still don't understand why it was ruled out.
Longstaff is offside in the build up, so they're saying he was interfering with play in the second passage, ie the ball is played off him and goes to Isak who does his magic footwork and sets Anderson up. Makes no sense as the defender just kicks the ball against Longstaff and the ricochet goes to Isak, Longstaff really didn't know anything about it.
I that note Longstaff was great last night too, he's becoming very dependable.