Falcon 9 deorbit sequence question

[4353]

I wonder if anybody here with insight into the matter can help me to some info.

For a typical SpaceX Starlink launch, what is the deorbit sequence for the Falcon 9 upper stage?

I assume it is this:

0) payloads release
1) possible Falcon 9 avoidance burn to get away from the payloads
2) Falcon 9 deorbit burn
3) Falcon 9 excess fuel blow-out.

What I want to know is whether there might be a fuel vent *before*  the deorbit burn.

This in order to interpret camerarecords of a recent Falcon 9 pass close to deorbit. In the record, we see an object envelopped in a diffuse fuel/exhaust cloud, followed a few minutes later by a sudden brightening. I contemplate this sudden brightening being the actual deorbit burn (there is some evidence for that), but why is there a fuel cloud *before*  this burn, if it is a burn?

Many thanks for any insight in the matter... 

[Jim]

Which videos?

[4353]

Which videos?

Images by Spanish meteor cameras, capturing the Falcon 9 upper stage from the Feb 16th Starlink launch on its final revolution, some 20-30 minutes before deorbit over the Indian Ocean. I am currently cooperating with with my Spanish colleagues in analyzing the imagery.