I agree that target panic and pressure are wildly different concepts. By very definition, panic is anxiety produced by unfounded fear (APA, 2013).
Target panic (in my opinion) is a maladaptive mental state that elicits a sympathetic (fight or flight) reaction to the act shooting a bow. This characterized by self-doubt, typical physiological responses to stress, anxiety and fear. This fear, commonly referred to as freezing can manifest itself in different ways to the archer; inability to obtain full draw, an archer finding themselves unable to release once at full draw, or even being unable to move the bow arm to the desired aiming point.
Cognitive behavioral therapy in form of blind bale shooting and clicker training is great aid in alleviating this condition. The fear of what will happen after the shot is mitigated by close range shooting without a target while the clicker introduces a conducive thought process to an archer's shot sequence by way of redirecting the archer's attention during the shot. It works great; if it helped me it could help anyone- I had it pretty bad.
Loss of shot control is bad habit. Depending on the archer's personality, this can evolve into target panic, or exist without consequence (other than having the potential to harm accuracy).
Pressure, as it pertains to the archer and their shooting ability is a slightly separate topic, although the Yerkes-Dobson law sums it up well. I don't know enough about this concept off-hand, but I'll do a little research and share my findings.