Money in the bank. He can not retract that statement.The owner of the security company has apparently replied in the comments section of the article...
F'n dumb. By just doing that, it shows how unprepared he is as an owner to deal with this issue. His original decision was intended to protect his business but he clearly wrote it from the emotional/ego side of his brain and forgot there is no justification for violating an employees rights. The timing of all the events will make it hard to prove the OP was not fired purely on the assumption he had a rifle in his vehicle. Consulting with his attorney first before he wrote that policy and memo would have saved him a lot of time, heart ache and money.
Termination will stand. $100k will be deposited in OP's bank account in 12-13 months.