I agree with Rueben. If you look at the start of the play (not clear on the replay, but easily seen on the first run-through) the player in black looks downfield and sees a player in green who will be going for the disc. Knowing that another player is likely to be in the area, but choosing not to look in the direction you’re running, does appear ‘reckless’ under that rule.
It is generally reckless to run without looking where you’re going unless you’re certain there is no one in that space. When you know, as here, that someone probably IS in that space, it does definitely appear reckless.