When I made a trade to an Ice race to get the Ice tech for my Rock tech, the log displayed that it was a successful trade but I already had Rock tech. Basically it switches the Give and the Get items around.
This was already reported, but it was said that the log was incorrect but the trade still went through. This isn't the case when I made the tech trade, as I still didn't have the Ice colony tech in my inventory.
Hope that makes sense
