Oh, sorry, you wanted specifics. I'm not sure what the point of the referal is, so can't be specific but what about:
"I understand that DS has been given a detention as he has been late this week. Of course we accept that he has been late - there is difficulty at the moment because his normal buses have been disrupted by the major road re-workings at XXX junction.
I understand that he should have had a referral letter or note in his planner for a referral to meet XXX HOY at 8 am the next morning, but unfortunately neither he nor I have seen this. This is why he did not attend the referral meeting. Could you please check that notice of this meeting was issued, and if so through what channel so that I do not miss it again?