As you can see from the chart, there was no bull strength during the first five 1 minute bars. No bars went above the previous bar or closed up strong. Such a first bar is worth shorting.
On 2010-12-21, we had a similar bar but shorts below it ended up in a one tick failure (1tf). Yes, the bar overlapped the previous day just a bit, but that by itself is not a show stopper.
Zooming into a 1m chart shows us how the bar was different. The first three minutes had strong bull action and bulls simply saw the bear bars as a buying opportunity at a better price.
Especially on a possibly small range day, its important to get in early on a possible AM move. First reversals are an important part of this trading principle.