Did anyone else notice the object flying by @ 54:26? What was that? Looked bigger than a piece of dust, was moving much faster than the upper stage and payload. Is that normal? Did it pose any risk?
Interesting find! Earlier in the feed you can see a solid piece of oxygen [0] bouncing off the engine. The particle you mentioned is going past the spacecraft (forward), so I can't see it being solid oxygen. My guess is a piece of dust that is being illuminated, and the camera is picking up the reflection but is blurry, making the particle look bigger than it actually is.
It happens right as the spacecraft is recoiling from the separation impulse, so I'd guess it's something coming off from the top of the stage and passing by the camera.
They explained at another point in today's stream that the pieces you see flying around are solid oxygen from a drain on the second stage. Totally normal and you see it on every one of their launch streams!
A couple inches to the left and that dialog would have been comedy gold :b (Although more seriously, I'll speculate that it looks larger than it is because it's reflecting a lot of light).
https://youtu.be/TXMGu2d8c8g?t=3265