I have no before and after pictures, because I didn't know anything weird was going to happen and the after picture just looks like someone didn't time their attack right and turned around. There were 7 squads incoming to an outpost with an ETA of 2 left (with an original ETA of 3). I ion cannoned this group and rather than one squad moving back, one squad moved forward. I deduced that they turned their squad around while I was ion cannoning and after refreshing the page I was right. So now 6 squads have an ETA of 1 to get back and 1 squad has an ETA of 2 to get back. This is likely a hard to fix lag issue that's too uncommon and not big enough of a deal to bother with, but I thought I'd bring it up.

i dont see whats wrong,
its fine, u just shot at a squad now the ship will travel slower because it was hit
the ion cannon only shoots 1 squad at a time so 7 shots will delay them all to eta 2
this is not a bug but sometimes it can be mistaken lol
i knew some other player with the same problem.

But I should not be able to ion cannon a retreating squad, I should only be allowed to ion cannon an attacking squad.

not sure, maybe they turned around right after you ioned them?

yes you shot a squad but seconds after the same player is online and sends squads back!