You can use a 12 point tool on 6 point bolts and nuts, but to do it correctly, you should use the correct tool for the bolt and nut. Of course, all bolts and nuts should be torqued to spec...but not everyone does that, which didn't make it correct.
My guidance, in the shop, use the correct tool. On the trail, use the best tool you have available and don't bring the shop to the trail.