They will give probably give your friend a credit but now waive the fee. Happened to me on a cruise with Verizon and my parents and they gave me a $30 credit which was better than nothing. They did state that they should have put the phone on airplane mode and they were absolutely correct.
We loved Horizon. Did 8 day Southern 3 years ago. Actually we're doing 8 day Southern on Celebration this summer. Once a month they have an 8 day going to the ABC islands so we jumped on it. Good look. I'm sure either choice will be fun