Pitcher balk ?- throw to 1st

[SAump]

Someone please check on the legallity of disengaging from the front of the pitcher's plate.

In a previous CWS balk video and earlier thread, a pitcher steps toward third with his non-pivot foot and then immediately executes a jab step in front of the rubber with the pivot foot to disengage and turn towards first base. The ruling is not a balk.

In the latest NLCS thread, stepping backwards off the rubber is considered a move from the rubber by a group of MLB umpires.

I can't find one written example, a video explanation or case play to validate these two "paranormal" calls.