Unexpected behaviour with instance mocks/overload

[diedexx]

The Mockery docs about overloading mention:

Using alias/instance mocks across more than one test will generate a fatal error since we can’t have two classes of
the same name. To avoid this, run each test of this kind in a separate PHP process (which is supported out of the box by
both PHPUnit and PHPT).

Instead of a fatal error, I see some odd behaviour that could either be a bug or something that should be documented:

I can overload the same class multiple times in the same PHP process. When I overload a class twice in the same test (which I did to find the limits of creating instance mocks), I found that only the expectations of the first overload are taken into account. Any assertions on a second overload of the same class are ignored without warning.

Here's the code that I used: https://github.com/jrfnl/bug-report-reproduction-scenarios/tree/mockery/overload-implementation-question

Am I interpreting the docs incorrectly? When should I expect a fatal error when creating instance mocks?