Damn, should have guessed memory as error source. I was wondering why sometimes I got the exact same results in consecutive runs and by something trivial as commenting a line the output changed. Thanks for the fast clarification.
To follow up your proposal within the issue on GitHub:
Does .contiguous() only align the data within the memory or does it copy it? In other word, has x.expand(*).contiguous() lower memory requirement as x.repeat(*) or are they basically the same?