Your post title is making a claim with absolute certainty. If you can’t see that, I can’t continue this conversation.
Your stills of the hand clearly show a cross dissolve. The problem you’re having is that this is the first time you’re looking at this kind of stuff, making you totally not an expert (which is why you boldly claim “White House uses AI” without any proof other than finding an out of context still with 3 fingers)
Since you’re so hung up on the finger stuff: the cut just so happens to align his fingers move up and rotated towards him in the two frames that are spliced. You can clearly see the leftover blur from the disappearing pinky and you can see his left hand rotated towards him causing his left pointing finger to be obscured by his left middle finger. That explains why you think the length of the finger is incorrect too. The hand simply rotated between the cut.
So forget the expert part, just look at the evidence I pointed out. The absolute zero benefit at all to Trump to “deepfake” his finger in a statement where he was about as hate-speech and on brand as he could be, should be evidence enough for you to walk away from your absolutist title of the post. But seeing how you struggle with concepts of what constitutes an expert, and don’t understand that your post title is very much a claim that you are 100% certain, I’ll leave it this.