Here's a link to KY OT info to start from KY education website.
http://www.kde.state.ky.us/KDE/Instructional+Resources/Exceptional+Children/Forms+and+Documents/Occupational+and+Physical+Therapy+Guidance.htm
If you request the testing in writing, I'm pretty sure they have to comply. They might try to tell you they don't have to, but that's not really true. Check out your rights at http://www.wrightslaw.com Do please go to this website and sign up for their newsletter as well. There is a wealth of information to be had in one place.
What were they trying to do that you didn't agree with? Did you agree with their testing, but they didn't go far enough to get to the root of the problem? Did you not like the goals or methods used? You are as much a part of the IEP team as everyone else involved, and they can't proceed without your consent. The more info we have about the situation, the better answer you'll get.
I would write a letter requesting the testing you feel your son needs. Make a copy and send it to
Special Education Attn:Jeanne Hettich
Bullitt County Schools
1040 Hwy. 44 E.
Shepherdsville, KY 40165
Make it return receipt so that you'll know she received it, and the timeline for them to act will be started. This is a great website for common form letters you might need. There is one specifically for requesting testing. http://www.aboutautismlaw.com/sample.html
EDITED TO ADD:
If you don't agree with their testing results, you can request an independant evaluation at the schools expense. The form should be in that form letter link, and you can find more information about that at Wrightslaw as well. Sorry they're making it so hard for you to help your son!
Good luck!