While reviewing some old tests I wrote a few months ago, I realised that one of them should not have passed. Upon further investigation, it appears that TEST_ASSERT_EACH_EQUAL_MEMORY() treats the expected argument as an array rather than as a single value.

https://github.com/ThrowTheSwitch/Unity/blob/master/docs/UnityAssertionsReference.md#test_assert_each_equal_memory-expected-actual-len-num_elements