What do you think...Bad trans, or bad converter?

Not if it was only one or two high gear charges. The seals, plates, or frictions could be going and it will take a while for the heat created by the bad parts to get into a large enough volume of oil to be visible and smell. Every convertor I had that went south made noises of some sort because the bearings came apart, or lost performance in every gear when the fins bent over.