A problem for Microsoft? or one by Microsoft? Yes, sure it's caused by Microsoft, but it has to be fixed on the LibreOffice side, since I am sure Microsoft won't do anything about it.
This is also Microsoft's problem.
Also, the cost of a Windows+Office license is so small that pretty much any company will happily buy it for an employee.
You can't really fix something when the spec is incomplete, ambiguous, and refers to non-disclosed information, all the while multiple official implementations exist that contradict both themselves and the spec about the behavior to have.
Now what about Microsoft implementing ODT correctly?
EDIT: Unless, of course, they have a private internal standard...