With that honey level (~2.6 lbs/gal) you have a mead that didn't start too high (I tend to average at least 3 lbs/gal and have an average OG in the 1.1teens). I know that yeast strain pretty well, I'm sure you finished bone dry (FG less than 1.004). If you're getting a tiny amount of petulant carbonation, it may just be dissolved CO2 from the original fermentation coming out of solution. I've encountered similar phenomenon with some of my meads (and I've never intentionally bottle conditioned a mead).
If you want to reproduce results, follow your same procedures, and see how it goes! (Report back upon completion........)
Packaged: Red X Weimea SMaSH
Recent Meads: Mead Day '11 Ginger Metheglin, Mead Day '12 Traditional (orange blossom) Mead, Simple Cyser '12
Secondary: Why do I keep this line here...?
Bulk Aging: Cocobochet, Wild Cider, Simple Cyser
Planned: Hop Metheglin #3 (NZ hops), Trad. Gesho T'ej