Welcome to the Bobcat Forum jbc!!!
I have a 773 Turbo which the same model as the S185 before they changed naming conventions. I have only changed my oil twice and seem to remember only refilling with about 8 quarts, maybe a hair more. I filled the oil filter, not all the way since it is mounted at an angle, to pre-soak the element before installing. Maybe the recommended amount doesn't account for the volume in the oil filter. Sorry, I didn't measure the amount of oil I drained out. What was your engine oil level before draining? Could it have been overfull? You mentioned the oil was less than halfway up the stick? Do you mean halfway between the low and full marks? I don't have access to my machine right now, but I think the high oil level is only about 1.5" - 2" from the bottom of the dipstick. I should only be about 1 or 2 quarts range from the low level to the high level on the stick.
BTW, what type of oil did you use? Just curious, I am going to use Mobil Delvac1 5-40 on my next oil change.