I think 'suspicious' is a little too strong, 'cautious' would be the word I'd use.
Dr. Wolpoff, in this apparent 2001 article, seems to be muddying the water by raising doubts about mtDNA to bolster the multi-regional hypothesis that he, along with Alan G. Thorne, helped originate.
While we don't thoroughly understand the workings of DNA and mutations, we've got a pretty good handle on it. So caution would the proper guide when dealing with this data.
In the intervening 5 years there's little evidence that's turned up to support the multi-regionalists, and a great deal that supports Out-of-Africa II hypothesis.
My take on this article is this is 5 year old argument by FUD - Fear Uncertainty Doubt.
Just my opinion of course.
From a Wolpoff article in Scientific American:
If a worldwide invasion and complete replacement of all native peoples by Eve's descendants actually took place we would expect to find at least some archeological traces of the behaviors that made them successful. Yet examining the archeology of Asia, we can find none. For instance, whereas, the hand axe was a very common artifact in Africa, the technologies of eastern Asia did not include that technology either before or after the Eve peiod.
Just one important fact to muddy the OOA hypothesis...