I don't know that 'intent' is relevant here, but IANAL.
The idea put forth is if something is confiscated without cause, it is by definition 'theft'. If something is confiscated without cause, kept then with no documentation is not able to be found then that is evidence of stealing.
If a LEO puts you in his car and drives off without RAS, no crime committed, and you do not give consent or against your will, it's kidnapping. Angry (perhaps off-duty?) cop has done this recently and was charged, IIRC.
If the equipment was destroyed there should be reproducible records of such. We just can't have things being taken and then disappear without consequences.
But, true, six years, it's more a lessons learned than actionable in this specific situation.