Although unlikely, it could be faked, for some reason. I can't be sure it's 3 minutes unless I had some sort of node plugin installed that timestamps the block the moment it receives it. Anyway, it was probably an accident that occurred in the meantime.
It isn't "faked" in the usual sense of the word, since there is very little incentive for a single miner to fake a timestamp. What constitutions an acceptable block timestamp is actually quite broad - anywhere between the median time of the last 11 blocks (plus one second) and 2 hours in the future (based on adjusted network time). Most miners keep timestamps fairly accurate, but they are free to vary them within the (on average) 3 hour window these rules stipulate. Sometimes miners have latency issues (which might also explain why they are mining empty blocks), and some may vary the timestamp as an additional nonce field.
It's not that uncommon to see a block with a later timestamp than a subsequent block, but it is a bit more rare to see a block with a later timestamp than the two subsequent blocks.