Not every city administration is up to speed on POBR issues. I wouldn't be surprised if they put him on administrative leave without providing him notice of the allegations against him that were being investigated. But, that's easily correctable ... They just have to follow the rules, notify him of the nature of the allegations against him and then take it from there.
I have found that a great many cities do not entirely understand that even department heads hired and appointed by a city manager and/or city council are also subject to the same employee rights under the law. It's a common misunderstanding by cities.

