Sure, that number is too high. But I am reminded of a normal person who tested their blood sugar after a couple of bananas who had an abnormally high level. The trick was it went to normal in 2 hours. And when you're sick your sugar levels have a tendency to go up higher anyway.
Since you got him checked with a doctors already, really one of the best investments for any household nowadays with diabetes so rampant is getting a meter. You can keep an eye on him now and make sure he's okay, but later when he's well you can also do a fasting test, a 3 hour after you eat and before bed test for a few days and find out if he is having non normal numbers. Then you can go to the doctors and show them the results.