Add inline commentary about OnKilled() override

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableStrongNestedHit.cs

@@ -22,6 +22,10 @@ namespace osu.Game.Rulesets.Taiko.Objects.Drawables
         {
             base.OnKilled();
 
+            // usually, the strong nested hit isn't judged itself, it is judged by its parent object.
+            // however, in rare cases (see: drum rolls, hits with hidden active),
+            // it can happen that the hit window of the nested strong hit extends past the lifetime of the parent object.
+            // this is a safety to prevent such cases from causing the nested hit to never be judged and as such prevent gameplay from completing.
             if (!Judged && Time.Current > ParentHitObject?.HitObject.GetEndTime())
                 ApplyResult(r => r.Type = r.Judgement.MinResult);
         }