yes it seems.
Yesterday I show it to a colleague and he realized that this number is the minimum int64 number you can store in a machine
     import numpy
     print numpy.iinfo(numpy.int64)

Probably pytorch check the value of the tags at a C level because if one does:
       numpy.iinfo(numpy.int64).min>=0

That gives you false, not true. We were discussing that at a hardware level this kind of extreme numbers is not processed as other numbers for speed.
I will open the issue