Bug or intentional?

[Stoli151]

Every now and then I come up from below on an enemy fighters six (offline) unnoticed and light him up with a good 1 to 2 second burst in which it was obvious to me I scored hits(smoke trails from engine, etc.) but the enemy plane nor his wingmen react. Then if I move into a position where I know they should see me they suddenly start taking evasive maneuvers. I was wondering if this has happened to anyone else and if it was a known bug or intentional(e.g. a rookie pilot freezing upon taking fire that he had no idea where it came from)?
On a side note, it really is a shame they stopped developing this. I got this game a few months back and am really starting to enjoy it. I've been using the Enlightened Florists campaigns, and have been able to set it to 100 minimum aircraft and 150 maximum with pretty good performance. Really interesting flying, swarms of blue coming across the channel. Very cool even if there is no point(no progression, ranks, awards, just fun) Anyways if anybody knows of better offline campaign stuff let me know I would appreciate it immensely. In the meantime I will be holding out hope for the modders.