Found a bug in the Audio Play action.
My states were all getting hung up on the action unless I was using the Finished Event feature of the action (which only fires the event when the audio is done playing... usually not desirable behavior, sometimes I want something else to happen right after starting a sound). My usual work-around was to manually send a delayed event right before using the action.
Looking at the code of the action, it will never call Finish() unless it either fails to play anything, or alongside calling the Finished Event selected. Normally, it will return out of all functions instead before Finish() is called.
If you don't specify a Finished Event it will hang on the action forever, and if you do it will only finish when the audio is done playing. Definitely a bug and not predictable behaviour.