It looks like those statistics have summer months included. That changes things from "60 hour work weeks when school is in session" to "60 hour work weeks amortized over a year".
In addition that study notes that teachers are more likely to work a second job, something a Google engineer wouldn't need to do to make a decent wage.
In addition that study notes that teachers are more likely to work a second job, something a Google engineer wouldn't need to do to make a decent wage.