I see how you could interpret it that way. The 'unless it is airbourne' only applies to the second action in that sentence. Grammatically, I believe that it can be read both ways, with the 'unless it is airbourne' applying to either only the second part or both parts.
If you want to, create a thread in the game suggestions/feedback and request that the text reads as 'Delay the target creature for 1 turn (cumulative), and unless it is airborne, attack it.' or something.
Edit: If nobody has replied and you have a new point, just edit your last post. People will see it changed.
Also, did you go to read this first (
http://elementscommunity.org/forum/index.php/topic,11503.0.html) before posting here?