from my personal exp, when intra is in line with daily and you are shorting at 2pm, its either for peanuts or slaughter. Post 2:30 the weaker side starts giving in first and its mostly those on the opposite of the line, ie. shorts here.
i thought i will write as soon as i read ur post, rather waiting for it to happen and then comment. Anyway, as said, most of the time thats what happens IMO.
Edit: I factored opposite move for expiry on monday, that is selling on wed or thu. Yest most of the pain was absorbed, but no one can predict the last hour of a monthly expiry thursday.