I have seen this a couple of times on other proposals and do not suspect foul play. It would be pretty dumb to try to boost commitment numbers artificially by
registering twice with the same email address (note that the avatar is the same).
What has happened is that the person initially committed as an unregistered user, and didn't link properly to their existing Stack Exchange account. He then unintentionally committed again when he came back when logged in. If the person had been active on Area 51 before committing to this proposal, it might raise suspicion. But in this case it is the only Area 51 commitment he has.
In the other cases I have seen, the commitment with only 51 points disappeared after a while. I am not sure why this one has lingered. It might be most effective to get in touch with the user and show him how to merge the accounts.
It would be useful if there was an automatic process merging unregistered users to accounts of registered users with the same email address.
EDIT The iisue of doubled follows or commits occurring when a registered user on another StackExchange site comes to Area 51 for the first time is actually a pervasive one. See, for example "Matt" and the numbered user immediately below him on the Computer Science Education proposal.