I'd go for one of the two following options:
1. Tell him what you really think. Try to explain that unless there's a trend in AS/ALT/CRS deviations, it might be a good idea to hold the remarks a few moments. I'm sure he'll understand this (is this a rookie btw?).
2. Use irony:
"He's talking to you now"
"Gee - you really think so? Musta' missed it while I was drawing cartoons on the flight plan".