I don't agree, of course. About the arrest.
But, I understand it.
Fasting during Ramadan is not easy for all Muslims. Especially, being forbidden to even drink water.
Not that it was a deliberate snub or insult, but any Muslim would be upset to see somebody swigging cold spring water in the desert heat.
...and a Christian, to boot??
Don't mess with Muslims during Ramadan. Period.