About a 3rd of the field went overboard here. Some even reached 6♥.
When our East showed the shape and strength, West pictured hands with honours in the red suits, such as
♥AQxx, ♦KQxxx. Or
♥Qxxx, ♦AKQxx.
Maybe ♥Axxx, ♦AQxxx
All good but a spade honour would make slam unlikely.
After East luckily bid 4♥, West wondered whether East had a black or red king. The ♦K was slightly more likely but even then a 4-1 diamond break would skittle 6♥.
Or ♦K and ♠Q. Marginal at best.
