Update,
Our policy individual had no answers and our legal department has no experience with a similar actions. Legal referred me to the purchase card (PC) office to find out about the process for using the SF182 for training. The PC office informed me that only the PC holder can obligate and this happens after they obtain an approval number/charge code from NERP. Based on the information provided by the PC office, legal has determined that this is a UAC. The best reason I got for the decision is that although, the SF182 is not cover under the FAR, using a purchase card for a class which already occurred falls under the realm of a UAC.
The closest I got to a policy is the SECNAVINSA 12410.3 but nowhere does it say the training officer has the right to obligate.
Thanks to everyone for your guidance