Well if we're going with "I read somewhere" then my non-cited source that I vaguely remember said that originally they weren't going to have the shot of everyone in the paddy wagon but when they first showed the movie to people to test it out before release everyone was all, "Wow, I didn't expect Kim to KILL Shego," so they added that to show that, in spite of enduring a way more than what it usually takes to kill a Disney villain, Shego still survived because apparently she's related to Wile E. Coyote (Super Genius).
I'd be interested in knowing why the felt the need for the huge difference in final outcomes for Drakken and Shego in the first place.
Drakken's comeuppance is having to say Ron's name. That's it.
Shego gets:
1 Kicked with such force that it should have killed her in itself but we can ignore that because over the top cartoon combat.
2 Off of a roof, which is how Disney villains, of which Shego is one, die.
3 Into a concrete-looking tower hard enough to shatter it, which should be deadly.
4 Hit with enough electricity it should have put the execute back in electrocute (now you know where the word comes from, you're welcome, originally it only reffered to getting lethal electric shocks)
5 Falling from there which is how Disney villains... just see point two.
6 Having the entire tower collapse on top of her, which should have killed anyone or anything.
Five and two are the same thing, so we can toss one of them, 1 is ignored for artistic licence. That still leaves four times that any reasonable observer should have believed, "Hey, Shego just died." Four times in rapid succession.
If they'd stopped after the kick then cartoon the laws of cartoon violence say that Shego would probably live, but once they showed that the kick sent her off of a roof ... they could have stopped there, not interacted with the tower in the least, and people would believe that Shego died. Then they added in two more obviously lethal events, and again they could have stopped. Shego could have gotten her costume caught on the tower and it could have not collapsed, but they went on to "and then, after an interruption, shego fell to her apparent death after all" and topped it off by dropping a building on her. One much larger than the house dropped on the Wicked Witch of the East.
It's such massive overkill and then they dialed back the "kill" part of it.
There's a reason that Shego ended up being Wolverine in fandom, nothing less than "I can survive anything and everything," can really explain how she wasn't dead.
And, for comparison, Drakken just had to say Ron's last name.
Which gets even weirder because Shego was on defense for almost the entire movie. At the very beginning she tries and fails to kidnap Mr. Nakasumi, but after the opening credits roll the only thing she does is fight Kim when Kim has broken into places Kim isn't supposed to be in. Shego practically on the level of an ordinary security guard for the whole movie. It's not like she tried to make a Kimmie frappe in the movie.
Yes, Shego says some mean things. And words do hurt, but Bonnie's the one throwing them and messing with Kim's head more than Shego.
Everything comes together to make the overkill (emphasis on the "Kill" part) just seem really, really extreme. Especially if you consider that one of the scenes they filmed (which takes a lot of work for a cartoon and is why deleted scenes for such are usually just voices and storyboards instead of actual completed cartoon) was Kim distinguishing between supervillainy and hurtful words (high school evil, she called it) and saying that she doesn't break out the violence for the second.
-
Nota bene: I'm not forgetting that Kim doesn't know that Shego didn't know. I'm thinking here in terms of the creators who would have in mind what the audience knows and thus what the audience uses to evaluate the actions shown.