If it was a “clean block” it would have occurred AFTER the receiver touched it or caught it, as Edelman’s block was. What Edelman did was a good example of a clean block.
What Welker did was contrary to the rules, which have already been clearly stated.
There is a size difference between Welker and Aqib. If I was about to collide with a man that much bigger than me I think I would get as low as I could.