Time and Sales - Can many traders be on the other side of a large trade?

[Rusty3]

When there is a (relatively) large size trade, say 65 contracts in YM future, I understand that means somebody bought or sold 65 contacts in one trade. But, does this mean that there was one trader on the other side of the trade, or is it possible that 1 trader bought 65 contracts from many individual traders? I assume there may not be a way of knowing this, but I wonder if we do know whether the other side of the 65 trade is necessarily 1 trader or possibly many.

Thanks,
Rusty A