This question already has an answer here:
Sinn Féin has confirmed that one of their MLA's has removed a clamp from the front wheel of his car, using what appears to be bolt cutters, in Belfast.
This is from the BBC website.
I know the merits of 's for plural acronyms is covered at Plurals of acronyms, letters, numbers — use an apostrophe or not?
but my question is simply: is this a BBC mistake or is it becoming standard. I'd expected the BBC to be very precise on such matters.
EDIT: It was corrected on BBC website the next day.