of all the statements so far, compressor stall has the answer.
you should have asked him. why didn't you?
isn't it possible that he was using the radar to make a quick search for buildups before giving the answer based upon climbout visual observation?
and yes, its true that hail doesn't show up that well on radar, how often have you seen radomes blasted apart by hail.
Its time to acknowledge that if you ask a question and someone calls you ''stupid'' for asking the question, then don't deal with that person anymore (after landing).
I was flying with a copilot back in the 80's in a regional turboprop. It was my habit to have 121.5mhz tuned up to listen for ELTs as we were over very mountainous terrain. We picked up an ELT and reported it to atc.
ATC asked us to take a bearing on it. (get this folks) And my F/O said he would do that. I looked at him and asked him what he intended to use to take a bearing on the signal. And he actually pointed to the ADF.
(oh, for you magenta line kids, that stands for automatic direction finder and it only works in the KHZ range, and low/medium at that)
I calmly picked up the MIC and told him that none of our planes were equipped with VHF DF.
I didn't make the F/O feel bad but I did take the time to explain things.
So, ASK. You might learn something.
Asking on PPRUNE instead of getting it from the horses mouth would be like Buzz Aldrin asking on PPRUNE the thinking process of Neil Armstrong in selecting a landing site.