Wether you want to say getting a first down inside the opponents 40 is a "big deal" or a "big play" really doesn't matter.
I get your point though. It might be a little misleading to say that every quality position involved an "Explosive play." One's mind could see Retzlaff sling one 60 yards, when it really meant that they got a 1st down that mattered.
I'll be honest though. Explosive play sounds more fun than Eckel or big play. At LES, a 4th down 3 yard run to get the first down is rather explosive.