Sounds like a fair bit of pettiness from both sides.
As a senior player, I feel that Smart has the right to question aspects of the game plan. He doesn't have the right to refuse to follow it. If the coaching panel can't defend "in this situation, why A and not B", they haven't thought through the game plan very well. IF there is any truth at all (and I emphasise IF) in the suggestions that Smart was dropped for asking questions, I'd be appalled in the match committee.
On the other hand, if Smart does have a grievance with the coach, he needs to deal with it in house - not via his brother on talkkack radio.