Most autocast spells have separate orders for turning on/off and casting. For example:
"heal" = heal a target (the actual casting of the spell)
"healon" = set heal to autocast
"healoff" = turn off heal autocast
You can't detect if a spell is currently on autocast, but you can detect when a unit turns autocast on or off. You could use this to store current autocast state in a variable...
In case of spirit touch, given those 4 order strings, I'd say "activate" actually casts the spell and "use/turn on" sets the spell on autocast.