The consensus seems to be that if people find errors in papers, they should contact the author directly, not post a question here.
Unfortunately, it seems that we haven't enforced this policy in this thread. There is an answer whose sole purpose seems to be exactly this – to point out a possible mistake in a specific paper. This has already led to follow-up discussion that isn't really appropriate on this site.
I would suggest that the moderators delete both of these answers, and encourage the participants to discuss the possible errors offline.