Correct, as Buenchico says, and also your brother should face the fact that magistrates have heard all this stuff about being under the limit when driving but getting drunk afterwards before ! It is odds-on that the figures will show that he must have been over at the time of driving whatever he claims to have drunk afterwards.If he wants to fight this he's not thinking straight.Your mother knows and so does he know what the truth is.
Just suppose that, has he'd , presumably, feel bound to do, he calls your mother as a witness to support his case. First thing that happens in cross-examination is she shown her original statement to police and asked whether she's lying now in court or was lying then when she made the statement, because the accounts can't both be true.And what do you think the court makes of that?You've guessed it. And as a bonus, your brother and your mother will be seen as liars, and you brother will have disgusted the magistrates by dragging his mother in to lie on his behalf. And do you think they'll be lenient if that happens?Let your brother work it out.