Welcome,

I'm by no means an expert on the Airbus and I can't say if the engines were wind-milling at the time but an engine killed by FOD will likely not be turning at all. The cascading effect as debris moves downstream tends to shell out the engine. As proper airflow is interrupted the fuel is usually still flowing burning up the hardware. If oil stops flowing as a result the bearings will seize in very short order. Depending on the sheer volume of birds ingested that could have interrupted enough airflow to over-temp the engine. I would be interested and viewing the engine hardware/data as that would tell me a lot.

I'm going to guess the RAT deployed and that provided enough to keep the bare minimum systems running including it appears Alpha Protection.