I found it. Here is my script which would have been a much better question in my opinion, as this shows a really ambiguous behavior :

create table #Table1 (col1 int,...

Even though I agree that there is some kind of a very weird behavior in some cases (I could also find one example of queries, for which I even opened...

The same table name can be used to create tables for different owners, that's why you need to specify which table of which user you want to change...