Empathy [Reading People] allows you to make an Assessment to discover one of a target's unknown Aspects (YS 129).
Deceit [False Face Forward] allows you to provide a false Aspect to the reader attempting to use Reading People on you (YS 126).
On YS 114, the rules explain that if you get duped by a target who used Deceit to fool you into believing he had a particular Aspect, then you may have wasted your Fate Point, depending on whether the deceiver wishes to "place a temporary aspect on you... representing how he managed to snooker you."
My confusion:
If you Assess a target's Aspect normally, don't you get to free tag it (YS 115 "you don't have to worry about the usual time limit... for tagging until the first scene where you encounter the target of your assessment")?
So... why is a duped person being obligated to pony up a Fate Point if they ostensibly have a free tag coming to them?
Or is this only in cases when the duped person is spending a Fate Point to Compel the target/deceiver using that bogus Aspect?