Like White Boy said, There are a lot of Variables. You also have to put Genetics into account.
None the less, Five bucks says both you gents are using Clones. Thats your problem, Right now theres only about 15-16 hours of light out. Indoors the clones where getting a minimum of 18. They grew a bit then started flowering, happens all the time. Hopefully they'll re-veg or just keep flowering through the season.
Check out my Journal, You can see where two of my larger plants started to flower in June, but now they have begun re-vegging.
Chobble