No, the meter is okay. There's a 20% variance allowed in glucometers, so take that first reading of 375 and the actual range that would be within that variance is 300-450. Not a warm and fuzzy feeling, huh?
You did right by retesting. If a number just doesn't seem to fit, retest if you have the strips. I'd write 375 on the SS if subsequent tests are close. This is just one of those "what the heck is THAT???" numbers that everyone gets on occasion. But it's only one blip on the data chart.
Yes, a snack is okay to give. If he insists, he's hungry. It might boost his BG, but it'll be worn off by shot time. We just advise no food in the 2 hours leading up to shot time, so that the number you are basing your dose on doesn't include any excess BG from eating.
You're using U100 syringes, right? Can you eyeball a lower dose than .2? It may come down to mini-micro-dosing. But remember, this is his first day back on the juice, so just like before, it's going to take some time for him to settle into a dose, even a teeny one.
Carl