The javadoc for DateTimeFormat says
"For custom formatting, set the pattern() attribute to be the DateTime pattern, such as yyyy/mm/dd h:mm:ss a."
This is example is misleading. MM is for month, while mm is for minutes - the example uses minutes where month is expected.
Someone who isn't paying attention will use the example pattern and wonder why their month is always January.
example should probably be "yyyy/MM/dd hh:mm:ss a" (capital M for moneths, extra h for hours)