Reading threads such as this makes the non aircraft driving public scratch their heads. Every time we board a flight, it is with the assumption that the blokes up front know exactly what they are doing. After all, they have done it all before, probably many times, right?
Then we see "discussions" such as this where we see Pilot A says in this set of circumstances, do this
Pilot B responds with: No. In these circumstances the correct set of actions is this, that or the other.
And so it goes. How about a PA call from the cockpit along the lines of "We can't agree how to handle this so does anyone in the back fancy a go?"
Incidentally, the aircraft involved, according to the Qatar Source reported a "smoke warning alert". After returning to Doha the following day, it was soon back in service, flying in short order to Riyadh, Shanghai, Cairo and is currently in Melbourne. Doesn't sound much like an aircraft that has had a fire of some sort (no smoke without....)