He could simply be trying to cover his tracks.
You could very well be correct, but I don’t think so.
I do believe that AG Barr already knows the answers to the question to be put to Steele.
If we are speculating, is its not possible that back channel talks were made to the Queen representatives about what we know of her government’s involvement in the coup d’tat of an American government. In exchange for keeping the British Government out of the line of fire Steele would have to become a witness for the prosecution.
There is so much we don’t know. So far only one side is talking and they are spinning everything even when it contradicts what they said earlier.
They say the wheels of justice moves slow so I guess it will be awhile before we know if those responsible are brought to justice.
The Queen is just a figurehead and has little real power.
But, I do think the Brit government was involved and that President Trump's team has told them that there can be serious consequences if they do not now cooperate. In turn, I think they put unbearable pressure on Steele.
If I was DJT, I would be strongly considering an ultimatum of cooperate or NATO is dead. Essentially they were complicit in very dirty dealing in internal US politics.