Right, sorry, i forget the CBOE is in Chicago, and the times shown are Chicago times, so 3pm is actually 4pm New York time.
I suppose that the last 15 mintues of trading (the index options and QQQ options trade till 4:15pm EST or 1:15pm our time) could change the P/C, but it would take a whole lot of calls to skew it from 1.2 to 0.8. Too much IMO to account for that much skew.
The most likely explanation is that Stockcharts has a data error.