The truth is, there finding it's not really necessary to change the trans. fluid at 50 hrs.
From reading posts in the orange forum, they have eliminated the 50 hr, and changed the interval to the normal 250 or 300 hrs, (I forget), on some of the Kubota's, to reflect this.
I expect to see that happen here too someday.
Some owners go nuts, and talk about some tiny metal pieces they found in the screen, when they did a 50 hr, (ah, that's what the filters are for), and advise not to wait.
One could argue why wait for 50 hrs, if your that worried? Why not change it at 5 hrs? And, every 50 hrs. after that?
There has to be some sanity, it's expensive to do this, (unless your one of the cheapo TSC fluid users).
I put the used Permatan I took out of my GC, into my fairway mower. God only knows how many hundreds of hrs. were on the fluid I took out of the mower. The used Permatran in there now, has well over 300 hrs on it, running in the high time, well worn mower trans, and it's still clean, and clear.
Some will disagree, but I would not lose sleep over whether they changed it or not, at this point. Unless you see them drain, and fill it, you won't know for sure. But, you will be fine, either way.
Do it yourself next time, then you will know.