From what I understand, EU 261 is based on two paths;
- Denied Boarding
- Late Arrival (departure is irrelevant)
RE. Point 1. If your friend had a boarding pass and was denied boarding then thats the first payment
RE. Point 2. It took off 5 hours late, sure, but how late did it arrive? I believe that determines whether or not you get the second payment... .
[As an aside, I'm pretty sure BA will see this as one payment only given their history...]