But place a big enough obstacle along the route and these people could refocus their navigation around one static object, rather than on the less predictable movement of others in the crowd.
This is pure speculation of course.
Here's what my brother actually said:
Hello, Happy Birthday my brother.
What GV said he said:
Hello, The bird say my brought their.
Sounds like a case of poor cellular...
And that wasn't a 787 flying overhead, btw!
In 1750 Issac Newton became discouraged when he fell up a flight of stairs.