To continue, is it possible that the six seconds of N2 spool drop are connected to the loss of the rigid joint at IPT/Drive ARM? Is the IPT slowing, and converting its energy into a disruption of the contents of the IPT cave? Without the obstacle of the Turbine, is the pressure stage increasing rapidly in pressure, since there is no mechanism to transmit it to the LPT? The HP is still functional (and gains rpm, and 'added' fuel, sent by the ECM, to make up for the loss of the IPT 'barrier').
I don't think it happened that way, the IPT, in circling the case, cannot have stayed for six seconds?