Learn from this, ive gone about 6 years straight now without losing any because I learnt. The reason they are gone order, 1- Your grow partner did it or someone you showed. 2- someone saw you or your parked car a fair while back in turn found the plants and waited till now to rip them. 3- A lucky bushwalker(unlikely)
Next year don't tell anyone, don't grow with anyone and only visit and work at dawn.