In my opinion, things as trivial as that can be done slightly out of order. SOP is important, but not at the exclusion of good sense and judgement.
Consider this- SOP has us go to the cockpit first, perform a few checks, then go out to do the walkaround. When the inbound airplane is late, or it's about to rain etc, it's quite common to see a pilot go down the jet bridge and do the walkaround before stepping onto the plane. SOP? No. Sensible and safe? Yes.