No he mustn't have been. They might be able to dictate what devices/apps get used in grade school or high school, but that is because they are supplied by the school. But, in those schools, no one cares about page numbers...it's hard enough to get them care about the class, or the assignment!
In college, the instructor doesn't have that authority...nor would the instructor care what the students use...or even IF they
use an app...
So much for grasping at straws... lolz