Same thing has happened to me few times and could not figure out what it is. Seems like the con is flying straight ahead, then stop and in next second he is coming towards you at seemingly full speed.
I would think even with snap roll you cant do perfect 180 degree turn at ful speed and not to lose significant amount of energy.
Well, it happens so rarely that it does not bother me too much.
------------------
jochen Gefechtsverband Kowalewski
Units: I. and II./KG 51, II. and III./KG 76, NSGr 1, NSGr 2, NSGr 20.
Planes: Do 17Z, Ju 87, Ju 88A, He 111H, Ar 234A, Me 410A, Me 262A, Fw 190F, Fw 190G.
Sieg oder bolsevismus!