There is light and a repeated "click click clickty click click click click" sound. Not everyone has an iPhone. And even an iPhone likely has a glowing screen.
I don't imagine that this many was holding his phone above his head. More likely, if he was texting, it was held in front of him or on his lap. How would the light bother anyone ?
As for the 'click', I have a cell phone, it doesn't make any noise when I text. Even if you have one that does, you can turn it off.