Whilst I agree that an in depth analysis of the physical properties of inertia, momentum and acceleration etc is best debated in another thread, the assertion that the AC keeps accelerating after the throttle is closed on the only live engine is relevant to the discussion of asymmetric handling and certification.
My Two bobs worth.
I think the claim that the AC continues to accelerate under these circumstances to be, to coin a phrase from the ABC's Hungry Beast, 'A little bit bullsh*t'.
Aside from the logic of it all, take a look at the Performance graph provided by JT on the previous page.
The acceleration line continues to increase through Vef until 'engine failure recognition point'/V1 (Where the throttle is closed). It then plateaus for a very short time before there is a marked deceleration
prior to 'Initial Braking'
Vb.
To claim that there is enough residual/run down power in the single live engine to continue an acceleration at speeds up and around V1 after the throttle has been cut is a nonsense.