No, you did not. You saw a collection of Democrat politicians whose arms at one point were sticking out in the same position that arms stick out at the end of a Nazi salute. This happens all the time. I do it 3 days a week when making breakfast.

What Musk did was start with his arm down, rapidly raise it to his heart, and then forcefully thrust it out to the position usually shows in photographs of Hitler doing the salute. There are videos of Hitler doing that full hand to heart and then thrust gesture that almost exactly match Musk's gesture from start to finish.

When you track down the videos that the purported Democrat examples are taken from you will see that none of them did that. They were doing things like pointing, or waving to a crowd, or gesticulating while they talked, and in the midst of that their arms ended up in that position.