My brother-in-law has just won his appeal for dla but I just thought I would mention that his son who is his carer and took him to the medical was questioned about the care he gives to his father - I thought that no-one was allowed to speak at the appeal only the person appealing the decision or have I got this wrong but anyway it may be useful to be aware that this could happen to someone else at their appeal.
There are no rules governing how a tribunal hearing proceeds; the Judge is allowed to decide the order of proceedings and who can speak.
Appellants are entitled to bring witnesses with them to give evidence. So if your brother-in-law's carer was with him he would naturally be a vital witness that the tribunal would want to speak to.