I had this quest in my log but when i watched my friend win twice the quest didnt complete. Any possible reason?
Your friend won in Adventure Mode.
Winning in adventure counts too normally
No way. He was legend playing vs players
Need to go over to bug report forum. The trolls might have some smartass comments for you until you do.
Yeah it must have been a bug. Thats what i thought as well.
It may be a bug, but a bugreport without any hint how to reproduce it is completely useless.
I still encourage Player to report a bug, if the issue still persists.
Best way to report is is to record the screen next time: start with the quest progress screen, then start watching your friend until they win a game, then stop spectating and go back to the quest screen to show the quest has not progressed. Post that to
youtube.com, then include a link to that video in a post on the bug report forum (https://us.forums.blizzard.com/en/hearthstone/c/bug-report).
Also, check whether you have any of the “returning player” quests (“Return of the Hero” / “Ready for Action” / “Back in the Game!”). Several quest-related functions are disabled when you hold any of these quests, so if you do I suggest completing this series of quests first, then retrying the spectate quest.