Since you are following SLGS, a couple of suggestions for you. We don't recommend giving insulin if the preshot is under 90. If you get a preshot like that again, it is best to stall, don't feed, and retest again after 20 Minutes to see if the number is rising naturally on its own to where you are comfortable giving insulin.
Also, since Ben was under 90, I'd suggest next dose is 0.75u, since any number under 90 with SLGS earns an immediate reduction by 0.25u.