The TomEE Maven Plugin provides a configuration flag checkStarted. The flag is not well documented in the code base but there is a blog post by Romain, which describes the intended behaviour of checkStarted.
By default, the container startup is done asynchronous. In the context of a integration test (without arquillian) it is important to wait until the container is started in order to let the Failsafe Plugin do the work.
However, this mechanism is currently broken. Thanks to mawiesne for trying and finding this one.
I created a minimal example, which reproduces the behaviour. The log output cleary shows, that the plugin does not wait for a complete server startup. Thus integration tests are executed although the underlying container is not ready yet.