That's not my understanding especially since the rules prohibit buy backs before the end of the quarter (when a company would know for sure what the exact numbers were).
Do you know exactly what day the trading was stopped because of the coming end of the quarter? IMHO, it would appear that it didn't stop until at least the opening bell of the 29th of June.
2,100,000 - 360,000 = 1,740,000 (Total shares sold minus shares sold by 5/21)
17,740,000 / 66,726 = 26 days (Shares to sell / max. daily volume)
There are only 28 trading days between 5/22 and 7/1 (exclusive).
28 - 26 = 2 days.
IMHO, June 29 is therefore the earliest date they could have stopped, and that's assuming were able to trade the absolute maximum everyday since May 21.
Do you agree and/or do you have any detail regarding the schedule of the 2.1 million shares?