As far as I can tell, the paper you link definitely confirms the essence of what Miller Says.

The end of the link says "We here at Bell Laboratories were truly dumfounded when this visitor from an unknown school in Australia reported his elegant procedure and remarkable success. Our own people took considerably longer to move UNIX to an Interdata machine, not because they were not as clever but because they had a different objective: a portable Unix rather than a UNIX port. But I think they'd . have blinked before undertaking the heroic effort that Richard Miller did and he did not even have a Unix computer to port from. "

I cannot see that as any sort of dispute.