Karma vs Akali Bug

Hello i noticed that when you play akali vs karma karma's W "creates a tether between herself and a targeted enemy, dealing damage and revealing them. If the tether is not broken, the enemy will be rooted and damaged again". Just wondering how Akali w doesn't Reveal her even though karma's spell clearly reveals champs..... this looks like a bug. the main point is if akali is under tower it dosnt attack her even though she is revealed. I hope this is a bug and not champ favoritism.