Dr BeDuhn's first degree was in Religious Studies. His Masters at the Harvard Divinity School was on New Testament and Early Christianity. His languages include Coptic, Greek, Parthian, Middle Persian, Latin, French and German.
As far as being an expert in biblical translation is concerned, the comment by a former poster (hillary_step) in this thread is relevant:
You must remember that it is not that easy to find a scholarly reaction to the NWT or KIT for the reason than many Greek Scholars are also committed Christians and already have a firm set of theological standards by which they make a judgment and remember, that their beliefs have often been ignorantly and arrogantly attacked by the WTS in its publications. Professor J. BuDuhn is a 'pure' historian, not a theologian, he has no ax to grind in the issue...