If I may just address what you said, the normal drafting procedures used when you're dealing with a relatively small section--and this is a small section--would be to replace it all and then underline what is new. It makes it a heck of a lot easier to read than to say, “adding, after the ninth word in line seven, these things”, and then deleting some other lines. This makes it possible to read it, see what the new provisions will look like, without any scissors and paste. But the underlining is the new thing.
With respect to the question of why these things were not in the bill originally, it's because it is not a government bill. Clearly the Department of Justice was not consulted with respect to drafting this bill. It was brought forward by a private member. After the bill is tabled, then it's a normal process, when the House shows an interest in adopting a bill, to ask the department whether the bill will actually be as effective in reaching the goal that parliamentarians seem to wish to reach, and if not, what would be the things that would make it better.