If the crew are suffering from hypoxia, ie poor co-ordination, erratic behaviour, memory loss, then this is possible. They may have had the intent to do the right thing (auto response from their training) but been unable to carry it out correctly. Most of us on here have seen enough hypoxia training videos to see how poorly people perform if they don't immediately go on oxygen. All I am supposing is that they have not donned oxygen masks quickly enough. Useful consciousness at 35000' is only around 5 seconds from memory.