PAT25(?) announced that they have a visual on the CRJ. ATC instructed them to maintain visual separation and then proceed behind the CRJ. They didn’t. No maydays, no panpans.
It’s pilot deviation or pilot error.
What would you be interested in with the black box? If the TAWS warned the CRJ pilots?
It’s pilot error or deviation. You have the CRJ in sight. You are responsible for maintaining visual separation. Full stop. Instrument failure does not apply to your eyes.
TCAS doesn't give resolution advisories (alerts that say to climb or descend to avoid traffic) below 1000'. It does have a warning noise still, but from my understanding it's common for it to go off on approach due to all the other aircraft around and on the ground at the airport, so it may have been ignored.