Engine cutting out

Hi, hoping for a bit of help. I've had my mk2 vrs PD170 for a few months now and twice during dpf regen the car has cut off when slowing down with the clutch in. Happened the last night approaching a roundabout, slowing down and as I pressed the clutch in the car dies. No juddering or anything, literally as if the key had been turned to switch the car off. Had to turn the key to off and on again to restart the car. It's been fine since. No warning lights and no stored codes.

Any ideas? 

Thanks