In real time, I would say if a dribbler is moving parallel to the division line, it would be very difficult to say whether the touches of the ball and the line happened at the same time, and when in doubt, the step on the line would draw a whistle. In the OP, it is somewhat easier to separate the two, in my opinion. With the benefit of the video, I have nothing.

Without taking sides (because I don't really know*):

Play: Defender B1 takes an otherwise-legal guarding position with one foot (a) on the sideline, or (b) on the division line. Dribbler A1 charges into B1.

Ruling: (a) Block. (b) ??

(* IRL, it's easy to call the dribbling play a BC violation because "everyone" will see the foot on the line and "no one" will know of any inconsistency in the rule.)

IMO, b = charge.

Bob's point being that the division line and sidelines are not both treated as boundary lines in the context of the rules.

"as similar.... as possible" :)

There are going to be obvious discrepancies in how they are approached. For example, it's not against the rules for a team to throw the ball into the backcourt; only to be the first to touch it afterwards.

In more than one ruling, from what I remember, though, they try to apply some of the same principles. I could see this being one of those cases.