This incident should not have needed the optimising tricks like banking to the good engine. It didn't need to maintain altitude. It just needed a descent rate that was 100 ft/min less than it had. An average descent rate of 500 ft/min for the 14 minutes of flight after the incident would have happily gotten them to the pub that night.
I'm interested that all radio transmissions have been modified in their wording for the report. There is also a discrepancy in the language between the preliminary & final reports. I don't understand why they would not append radio transcripts. If there had been an initial instruction to descend to 5,000 ft, followed by a further instruction to descend to 2,500 ft, then this whole incident takes on a completely different flavour. I raise this because of the ambiguous wording used in the report coupled with a difference in wording between the 2 reports.
For instance, the preliminary report says "ATC instructed the pilot to descend to 2,500 ft". The final report does not cite the ATC transmission, but says "The pilot read back an ATC clearance to descend to 2,500 ft". There is a fair difference between being cleared & being instructed. Which was it?