No mystery here. Just complicated electronics that do not like water or fire foams. Wet three numbers and it dial three contacts in what ever order you have them in. Wet 6...Wet 9 or all.
Very interesting. In my case, the phone wasn’t wet, but the train victim’s phone surely could have been exposed to foam or chemicals or water. Still, the family derives some comfort from the calls, so they will believe it was meant to be.