Shakespeare said:
Perhaps a bit of panic set in prior to some sound decision making and resolution.
As an ATR driver I could imagine, they have had an ECU failure after takeoff, which looks similar to an engine failure if you donīt look after the gauges.
It gives you an approximately 60% powerloss.
There is a checklist for ECU failure, which resolves the problem and you could continue the flight without hesitation.
So maybe somebody radioed too fast before looking, what really was going on?
Be aware, this is only speculation.