I feel iffy about it too. I mean, we may think Oh yes go for it it'll expose DrU! but how would we like it if our phones - which these days tend to contain almost every aspect of a person's life - had to be handed over to The Bill?
Could they just ask for the metadata, which wouldn't need his actual phone, which would show times and frequencies of calls to the BMA, but no more than that.
Notes on his phone? I suppose he could be instructed to download them, and as he's under oath... he should do so honestly.
Yes I know....🙄