i did a test and it appears that sometimes views get counted twice, but most of the time they get counted once.
i don't see it as a big deal... i personally don't like the counting feature, with posts or members for that matter... it's a feature that could easily be removed although it does create more hits on the site for a couple reasons:
members will view a thread that has a lot of hits on it out of curiousity... some members are also concerned with having a high post # under their names, therefore they post more replies...
i don't like it because it causes there to be many more short replies to threads... also, we see some members get upset when their thread gets viewed X amount of times and no one replies... the feature's only good purpose is to create more hits IMHO.
Rather it is an accurate method of measuring the hits. If there is a single post with no replies the hit is one. If there is a post with one reply then it is two hits and so on. If it didn't count that way a reply would never be counted as read.
Other forums act differently, for example the one on Yamamoto's page requires a click for each reply.