What it comes down to is that the pulldown can change anytime they needed a reel change when encoding the laserdisc. When making the disc, they had no concern if half a frame was interlaced incorrectly, since you won't notice it while watching. So no attempt was made to sync up the frames when reels were changed.

It's quite common for laserdiscs to alter the pulldown frames many times per disc. You can usually find the spot where it changes by scanning through cuts. Just be careful, sometimes it'll change back to the original settings by the end of the disc, making it easy to miss the change.