I'm using iterm2 v3.0.2 with fishs hell and tmux in osx. When I'm opening file via emacsclient and closing buffer - I'm successfully returning to terminal, BUT iterm2 window has no focus, so I have to click on window to gain it. I tested behaviour inside tmux session and outside - the same behaviour.
My command to run emacsclient:
emacsclient -c -a \"\" $argv