As stated by the last comment of Bryan Turner, in the linked Jira, the flag tinyInt1isBit isn't properly working for things like hibernate validation. The methode he states (columnTypeClause(String)) does seem to be the problem.
An example of the error hibernate validation throws:
org.hibernate.HibernateException: Wrong column type in <databasename> for column <columnname>. Found: tinyint, expected: bit(1)