I`m sorry to hear this , as it is exactly what Reuben was doing too . The trigger for Reubs seems to be the ball chucker , I dont send him running mindlessly , but it gives me better aim to send a ball into the rough for him to find . I did keep Reuben on lead at Golitha for some weeks , a long line and just reinforced recall over and over , the ball being the reward . I honestly cant say if Reuben will revert and leg it out of sight and can see why you are so worried , has he done this since his escapade ? I just took Reubs back to basics , and didnt let him off until I felt sort of comfortable to do so . Its only at this one place that he does it but like you , it scared me to think that I had lost control . I also worked on the STOP cue , which again has helped . I have him on a long line , I walk slowly with him ahead , then I stop and call Stop , only when he is walking away from me , then ask him to sit and stay ( still working on this ) and then recall him pulling him gently to me , much praise and a ball as a treat . Hopefully this was a one off for Toffee , you might also find some good advice on a FB group called Gundog Training for Novices , I gathered loads of help on there re the Stop x