I think it is safe to say the IBK does not have endless pockets to prop up stock prices of thier clients. My guess is they are fully allocated in what they can spend in POET. They are not a bank with massive trading desk with a war chect of money to be the hero on every dip.
Your right, anything is possible but in this case i doubt it. It just doens't make sense.
I have no afflicaiton with IBK but have had a little exposure over the years- and they are a top notch group that really believes in POET. Hence them saving POET's bacon last year.