All reactions mentioning here determine startle "reaction" as controlled, however the main idea is that the physical reaction in a startle is "uncontrolled".
Whether "fight or flight" principles make you go-around or not, the action remains uncontrolled by the brain. Your body might be doing things, in a startle the brain is not moving along.
Those people thinking your go-around will be controlled are missing the point of the startle. You personally will only know if you go-around or not if you're experiencing it. And if you're experiencing it, the fact you go-around or not is not that important. The most important thing here is that apparently some people think they can control it. You can't. Live with it. Don't think you are different.