Of course they did, it was blatantly exploiting a bug. There was nobody doing it that DIDN'T know it was wrong.
This shit wasn't a bug, it was an idiotic design decision, there's no mention of warnings or the like (had there been I IMAGINE the players would have stopped), making it totally inexcusable.
They said that most of the players involved with the trading exploit were only warned in the first place and not even suspended. Seems logical to assume that suspensions followed said warning.