Originally Posted by
Squawk7700
You saw and interpreted correctly CM, the passenger did indeed give a shoulder-tap as
a warning.
Unfortunately without further input a shoulder tap to a pilot during flight could be interpreted as, 'what's that', 'where's the sick bags', and a hundred other things before one might think about colliding traffic. That in no way is saying the passenger should have done more, they probably had no idea how fast things were happening until just before things hit. So a shoulder tap is about all you would expect.