Weird attack results when attacked while splitting units

So I was with my strong 90 units stack when I hear planes buzzing - 65 bombers fall on me. The stacked included 25 AA level 5.

I rush to split the units, and I am still doing my splitting when the planes hit !

- 15 units destroyed on my side

- I think 0 damage on the other side, at the minimum not a bomber lost.

I wonder whether it is possible that due to me splitting units I receive the damage twice, and inflicted none ?