There were only 591 Oct/2.50 Put contracts and 40 Oct/5.00s, representing a total of only 63,100 shares. When you add this to 1,109 Oct/2.50 Call contracts or 110,900 shares, there would have been neglligible impact on this past week's volume from potential purchases by all options traders to cover their positions, and those most likely to have covered (if they hadn't already) would have been the writers of 631 Puts representing a whopping 63,000 shares.
So while market forces may have indeed worked to cap last week's rally around $2.50, I don't believe the buying pressure has had anything to do with Monday's options expiration. That would have resulted from traditional buyers as well as some shorts covering their substantial positions.