Instead, he asked about environment minister Roseanna Cunningham supposedly putting royal security at risk through allowing two paths on the Queen's Balmoral Estate to be included in promotional material for walkers.
Ms Cunningham's intention, supported by an official reporter and the Cairngorms National Park, was opposed by the Royal Household, and a Home Office minister threatened to intervene to overrule her.
Conveniently, the fury of the Labour-run Home Office over this was leaked, putting the minister, who does not hide her republicanism, in a bad light. Labour clearly smelled pre-election blood, with a demand – apparently irony-free – from a former defence minister for Ms Cunningham to resign as she was putting lives at risk.
If there were a security threat to the royals, then publicising these paths, already open to the public, would make little difference. Terrorists can read maps and use satellite technology.
Labour's assault yesterday was a cheap shot, drawing the Royal Family into party politics. Mr Gray should be ashamed of himself for becoming involved in this pathetic – and unsuccessful – attempt to smear the SNP.