If they have not tested the actual aircraft - it is only an assumption that the aircraft is 'spin tolerant' whatever that means. If you are actually at the point of stall and you have a compressor stall on one engine then that engine gives high drag and the other full thrust - this will stall the wing with the engine with compressor stall as it slows down relative to the other wing with full power. The aircraft starts to autorotate -
Fanciful at best without actual numbers.
I believe there have been one or two events at altitude that prove this wrong