my initial thoughts, are that theres a lot of manual work involved with copying pasting reversing footage and holding. I could guarantee I could match that look doing it the laborious manual way.
But what could maybe do it faster? My first guess is the plug in
for AE by re vision. Twixtor Pro. You can enter settings based on “speed” so theoretically, you would have the footage playing at 100 speed, over 1 or 2 frames keyframe the 100 to 0. then hold a frame and keyframe a -100. Go back and forth to your taste. Thats my first guess. Twixtor Pro is pretty cool and works well in clean shots, like in that video. It does well with complicated footage as well, but occasionally will give you fits.
Messing with time displacement filters may also help.
SuperNova
Animation & Visual Effects
Scott Novasic
Los Angeles Ca
web:https://web.mac.com/finaleffects