I've had a similar case where 16 accounts were involved in send all their assets in one wallet [off-forum transaction], but after they proved my suspicions wrong, I happily removed the negative tag.
So you just bother people for nonsense accusation?
Do you think its right to bother people? While for sure everybody cares about there privacy?
For this forum exist for so long for sure many forum members do transaction for ones or even more, so this txid proof is totally nonsense at all.
And no one owes explanation to anyone since as I said privacy is more important, im sure that many people will do the same if they think the accusation is no basis.
Hopefully there's a penalty for people rising wrong accusation. Since they just do that for a show and for farming merits.