If the failure mode is being described accurately then it's clear to those who worked on hardware that these are not the sort of problems that should be encountered this late into the cycle (on Mars). Perhaps we just need more info on the situation. But as it currently stands, things smell a bit amateurish.

See also: https://news.ycombinator.com/item?id=27555761

The flight instability is, all by itself, ironclad proof of a design flaw. When a constant time-offset navigational input can affect real-time attitude control, that is a rookie booboo.

The exact nature of the design flaw is subject to further investigation.