Odd behavior on iPhone 5 with "Activation Required" message

Looking for opinions or prior experience on this one, please!

My wife has an iPhone 5. She was showing me a bunch of emails she received from a company called Zorpia. A search for "Zorpia" showed hoax links and that it was suppose to be from a Chinese social networking company. The emails appeared to be from a friend of hers but she had never heard of the service. I advised her to just delete them. By accident, one email got opened. When tapping the 'Back" button the Mail app crashed. Then the Apple logo screen appeared and then switched to the lock screen with an "Activation required" error message with an exclamation point next to it.

After swiping to the right, it said the phone was deactivated. To activate it, we needed to enter the Apple ID and password associated with the phone. This seemed odd but a search for Apple's support seemed to show it was the Find My iPhone Activation Lock screen. So we did that. After a few moments, the home screen came up but then what appeared to be the activation app relaunched and asked for the password again. After entering it one more time, It switched to the iCloud settings screen which again asked for her password. Once that was entered, the phone returned to normal and appears to be ok.

The screen we first saw was the first one shown on Apple's support doc: Turn off Find My iPhone Activation Lock - Apple Support

Searching around the forums here and online return mostly old results, some from years ago. I was hoping to see much newer results.

It felt really odd but the phone seems fine now. I'm wondering we should change her Apple ID password just in case.

Anyone else experience something like this? Thanks!

Added a line about the odd internet search results returned when searching for this problem online