[holden]

The load might've conceibably been within safety limits, but the pilot may have been "flying by the seat of his/her pants" (inertial feel, muscle memory), or even been showing off, letting airspeed get too slow, straying into the "area of reverse command", where s/he probably had little experience flying the a/c.

What I saw developing in the video (before the "point of no return") would've required dramatic, counter-intuitive control inputs that some pilots would shrink from doing, never having to do them before (outside a simulator).

OTOH, there may have additionally been a contributory hardware system failure that would've been beyond any pilot's ability to overcome.

/complete speculation
HF, CFII

[American Constitutionalist]

Would bird ingestion do this ?
A large foreign object into the engines ?

[Mat_Helm]

Probably hit V1 and V2 rotation velocity and on initial clime out something went terribly wrong. CVR and DFDR recorders will tell the story. At some point the stall warning tone and bitching betty came on. It may have been to late at that point if they could not get the nose down in time. It would have been a split second to catch and recover for do or die. If the cargo shifted it would have been unrecoverable.