Nice of the camera car to stop and offer assistance, Not!
to be fair in that situation I would have removed my vehicle from the roundabout before stopping to help
likewise Nibor and the way the camera car is traversing the roundabout is the busy way across it - double carriageway coming off and the main road from Oldham itself coming on.
There's enough clearance round that roundabout that nobody should (ha) join in the incident coming round it, so if they stopped to help or protect the downed rider, in reality they would have more been a vision blocker for anyone heading off up the same road the camera car took and could have made things worse for the guy.
Putting a probably non cycling drivers hat on for a moment too, I guess seeing the cyclist getting up and the driver out to speak with them made it a look a less serious shunt to get involved with. The clip cuts off quickly after, so while its doesn't look like it, we don't know if the driver did stop safely far enough off the roundabout and come back to offer their details and make them aware of the camera footage.