That won't be a valid expression. Any expression trying to reach the bytes property will return a false expression, and you will see a log on the server.
You will only be able to deal with regular dataypes on those expressions. (such as long, string... etc).
Perhaps we should make it more explicit on the docs.
Thanks for the clarification.
You could add a feature request in JIRA to extend the filter syntax to support array indexing operations, if you like.