So after all E6 isn't that fragile in tough conditions. Popular "wisdom" dictates that pro E6 is more delicate. Well, along the long life of these products and their evolution lots of efforts into preservation were put.
I have a few boxes of sensia that has a green cast in the deep shadows. I wonder what caused it... They went into tropical weather for a couple of months, passed 7 Xray scans and got processed 5-6 months after exposure (stayed in freezer). I doubt it was a processing problem (used a great lab). Still on date film as of processing time (two montsh before expiration)
The Kodachrome that accompained on the trip is perfectly fine, that film was deemed quite resistant.