The only document that matters is
The Guide To Judicial Independence which states
It doesn't mention any future contact, although it probably does mean that judge won't be able to sit on any case involving Samsung for a couple of years after he finishes working for them.
However it does also say
You could certainly question '
the appearance of propriety' given the period between the two events is quite short.
It would of course be best if sitting judges were required to take no external work while sitting but given the amount of money they would be passing up to do so - any lawyer who has made judge would be able to commend very high fees indeed - would mean the only judges we'd get would be retired old duffers. Oh no, hold on...