Something peculiar has just happened. A week ago a 300 point bounty has been added to this question (I think its content is hardly relevant to this meta question) [note: the bounty was added by a user other than the OP of the question]. I have looked at the question now and noticed something greatly peculiar - some new contributor has posted an answer stating the problem is open, the answer was upvoted and awarded the bounty, and just two minutes later the answer was deleted. The account has existed for 43 days so it doesn't seem to have been created just for the purpose, but the timing suggests this has been all planned by the bounty creator.
What could be the point of this? Is this behavior acceptable?
I don't want to assume malicious intent here, and deleted posts don't give reputation anyway so it might not be much of a concern, but I'm curious to better understand the situation and wanted to bring it to the community's attention and see how they would view it.