Dribbler Bears Responsibility for the Contact

[Kansas Ref]

Sometimes as an official and an observer, I will invariably see these two scenarios:

1) A1 dribbling along the sideline with defender moving parallel and in close proximity, then A1 just keeps on dribbling forcing his/her way into a narrower and narrower opening/path betw. B1 [defender] and the sideline, until ultimately A1 has no more room and is dribbling OOB on the sideline. Invariably, the player turns in an exasperated fashion towards the official and beckons for a "force out".

2) A2 is slashing their way thru the lane and encounters B3 and B4 [who were there first] in a double-team help defense, then A2 made contact with them and trips over the leg(s) of B3 and B4, and falls down. Invariably, a "block" is called on B3 or B4 despite the defenders(s) having been their first.

Invariably, I have seen fouls called on the defense; however, such calls disadvantage the defense---ostensibly unfairly. Has anyone else seen such and what has been the ruling or non-ruling?