Hi Claudiu - that was not said by me.
Indeed, the only things that could be said to have been experienced in that scenario – and all that was experienced – was that which occurred (existed), namely: a sensation on the leg, a thought of a spider, an emotional trepidation at the thought, and a verification that no spider was on the leg.
But since you are implicitly – if not explicitly – suggesting that it is possible to experience that which does not exist, then what approach do you personally take to verify the existence of anything?
Surely you cannot take the empirical approach as that would rely on experience and, as you are attempting to demonstrate, you are able to experience things which do not exist; or to put it another way, you are incapable of experiencing only the things that exist. Anywhere from 0.1% to 99.9% of what you are experiencing at this moment of being alive – the only moment you are ever alive – may exist, who’s to say? Certainly not experience. So determining whether or not something exists cannot, for you, be an experiential matter:
What then can you rely on, right now, at this moment, to determine whether something exists?