There's a few different Me262 types in the video.
The ship in question at 15:30, is a Me262A-2a, which was armed only with the two lower Mk108 cannon.
At 18:22, they are in front of a Me262 A-1a, which was armed with four Mk108 cannon.
Your best clue would be to look for the hardpoints - if the 262 has hardpoints, it has two 30mm.