Did the starter motor turn the engine over and the engine would not start?
If this was the case, Did you prime the HOT engine? If so how long? (We used to prime the Raven 2 with a hot engine about 5 seconds, I will check I have a check list at work)
Did the starter motor not turn the engine? If so
Was the clutch light still on?
Was the rotor brake on?
I used to fly an Astro a few years back we had a problem quite often when the starter would not turn the engine we use to hear a clicking noise and the engine simply would not turn, We had to turn the small cog on the starter shaft (Underneath on the back of the engine) when this hapened. Then it would start no problem, BE SURE TO TURN OF THE BATTERY BEFORE TURNING THE COG. If this is the problem then your maintance needs to sort it out.