OK Great! Next task is to work on the spreadsheet (SS) to reflect what is really going on. If I understand correctly, 67 is AMPS (AM pre-shot number). You correctly interpreted this to be too low to give a shot, so in the U column, change the 2 to NS. This will record the fact that you did not give a shot. If normal shot time is 6AM, +2 is 8AM and that is where you would record the +2 test result. Does that make sense?
Going forward, take a pre-shot number for both AM and PM and record those as AMPS and PMPS respectively. When insulin is given, the amount given is then recorded in the U column.
I know others have encouraged you to get rid of the dry, please be aware that changing him to a low carb wet food will also lower his BG and may reduce his insulin needs.