...except for bleeding speed and allowing the missile to continue its original trajectory...

the point of a notch is to go defensive and make the missile turn as much as possible while defeating pd and retaining lock if you have an aircraft with a gimballed radar capable of doing so if you've launched as well. he wasn't moving slow and had altitude, but decided to climb and bleed speed rather than draw the missile to a lower altitude where it has worse performance, and where he can make the turn you were talking about.

a notch is specifically designed to defeat pulse doppler, but is standard operating procedure for all all-aspect missiles since you don't know what you are facing other than the fact that it has locked you from the front or side.