If the beer was flat it means that the co2 hasn't been absorbed into the beer yet, and the gushing would be normal after only a few days.
If it's still gushing and it's carbonated, it could be over carbed, or there's a possibility that it's caused by an infection. (Doubt it though)
It usually takes at least 2 weeks for the beer to absorb the co2. It does get more pressurized, but that pressure is what carbs the beer.
I would just leave them for another week or two before trying another, and give it a chance to absorb the co2.
Since your FG was so low, I don't think that you'll have problems with bottle bombs or anything like that.