“If I’m not mistaken, a teleprompter speech can be changed on the fly.”
I’m sure it’s all digital, so it makes sense that the person doing the input could tweak it as needed.
Hillary’s speech -apparently- coming up
Here’s the link
https://www.youtube.com/watch?v=kHAlX9a_dfA
Here’s Mike Cernovich’s twitter - he will be live responding to her speech - he’s live now.
https://twitter.com/Cernovich
(forewarned - there will most likely be swearing there)