CO will show the scheduled time based on their expected operations while FlightAware shows what's in the filed flight plans. As the day goes on if CO thinks that they'll actually operate on time then they'll update the website with the early arrival. Or if things are not running on time in EWR they'll file new flights plans and the FlightAware details will update.

The easiest thing for your friend is to have them check co.com after departure or set up TripAlerts to email them.