Error of law if tribunal do not adjourn for outcome of ATOS complaint

I seem to recall, although I’m ready also to accept I may have imagined this, that there was a case (could have been UT but I think it was older than that when they were Commissioners) that determined that where it was made clear during a tribunal that a complaint about the HCP’s opinions or findings had been made to the DWP (aside from the actual appeal of the DWP’s decision), it would be an error of law for the tribunal not to adjourn to await the complaint outcome.

Supposing I have not imagined this, can anyone point me in the right direction to find this decision?

Many thanks!