ooooh...watch the "bubbles per minute" talk, them's fighting words around here sometimes. ha.
when you racked, you jostled things up a bit and got the yeasties to get active again and finish chomping things down. its' good and it usually blows at any remaining hydrogen sulfide.
like everything else, three identical hydrometer readings in a row on three different days will tell you when fermentation has stopped. i've never used that yeast before, but if it can take it all the way down to 1.000, way to go! please let me know if you do hit that, because i'll try it out if it can dry it down that much.