Tricky one to answer as a few factors can lead to breakages besides a fault with the pole.

A couple of factors not related to a pole fault or previous undetected crack are:

1. overtightened elastic and strong mainline combined with playing a lump.
2. over enthusiastic playing of a fish putting too much strain on the pole.

I’m guessing your top kit section folded as you either gave it the big one or no longer had enough pole or elastic to take the strain of the lunges of the large fish.

No.4 and No.5 sections on many poles are more prone to breakages when playing large fish most times when the elastic has bottomed and there’s no more bend left in the pole or no more pole to follow the fish out to turn it. Top kits will go the same way.

Sorry to hear you have had a double whammy, but can you be certain that the no5 had not had a ding before or that you didn’t force the fish to surrender…..

think grant albutt in maver match this final…..it happens to even top of the range poles,ive recently had a no5 go on a garbolino carp match so i know its a pain in the arse and especially since i couldnt get a replacement because the french were having there usual month long holiday