If Samsung has a policy for deleting emails after 2 weeks and it's proven that this policy has existed prior to this issue, then there's no deception going on. Is it "smart" behavior - probably not (in my opinion). But it doesn't make it dubious if that is indeed their policy. I don't know how long they've had that policy or if it is an actual policy/procedure across the company. Only what I've read.
So yes - they destroyed email that could have been used as evidence. But who here knows whether or not that was a deliberate act relating to the trial or just SOP
Actually, it doesn't matter if they have a two week policy or not. Once emails and other information is subpoenaed, it is illegal to destroy as it is now considered evidence to be presented.