Certain yeast strains chew through the wort faster. Also there can be airlock activity even after fermentation is done so yeah I would give the wit another 2 weeks and bottle.
When you say 72 degrees, how are you measuring that? Are both in carboys with good seals.. I've had a bad seal on a fermenter before and wondered why I had nothing in the airlock and pushed down on the bung then all the sudden I had bubbles.
How long has it been in there? The only downside to leaving it longer is that your dry hops will be in there for an extended period of time and may result in some grassy flavors. I typically add my dryhop 3 days before I keg but since I can cold crash this is no issue. 7 days is what I used to consider the max for my dry hops to be in the fermenter before packaging.
I would take a gravity reading and see where it's at. The only way to know for sure that fermentation is done is to take 2 gravity readings a day or 2 apart and if they are the same then it's done. What was the yeast for that? Likely it's done but a gravity reading should be taken either way to verify where it's at and get your abv plus other useful info like attenuation.