I would be very skeptical of the idea that just because someone's a police officer he is better suited to judge aircraft attitudes.
Knife-edge flying can be done by aerobatic planes, but in this case the nose was reported as about 10 degrees down.
There were no reported measurements from severed wires, merely the conjecture that such measurements were taken. We don't even know that the wires were hung in an arrangement that would make measurements diagnostic.
There were clearly quite a few people who were impressed by the plane's angle. That constitutes circumstantial evidence that the plane was in a steep bank. Opposing that evidence we have flight path geometry that rules out a bank steeper than the low 30's, damage to the right wing that rules out an impact at an angle higher than the mid-30's, and an impact sequence that best fits an approximate belly landing.
As Megan said, you can't trust witnesses.