Ohohoh. The craziest reason for the missile to go a little conky has got to be the energy management steering maneuver in THAAD (dunno if other missiles do it as well) - https://en.wikipedia.org/wiki/Terminal_High_Altitude_Area_De...
https://en.wikipedia.org/wiki/Sprint_(missile) https://youtu.be/YZZV464z9g8