That's just not how that works. Bending depends on how bad the break is and where it is and how much swelling there is. People break ankles and walk around on them for some days, after all.
I could bend my finger after I broke it... that day, anyway. The next day it was too swollen to bend it. This was a simple and clean break and healed well.
Similar with my elbow. I could bend it at first, then less, and then the swelling really started and I could just barely bend it. I could bend it a little for the xrays, even (I was to do what I could) Weirdly, it didn't even hurt that much just stopped being functional.
That's fair, but he didn't declare it broken in the ER after an x-ray. He declared it broken with a not visibly mangled finger, that by your own description would not have reached the painful point, so color me suspicious of the (probably) clout chasing youtuber.
Edit: well it could be broken, but I'm suspicious without further evidence.