In the top video watch the spindle around the 15 second mark in the slotting operation. It might be a trick of the light, but it looks like deflected notably. Perhaps it was pulling the toolholder?

I'm sure they did some hard math on this about cycle time vs. tool wear. I don't have access to a machine that couldn't do it, so I'd have to use a much slower adaptive tool path that would take eons.