Well. An uneducated lady from my take. the UR light coming from welding is more of a risk than actually starting a fire, though thers is still that risk of fire.
Next time be like, So you want your kids to be blinded by my welding then?
I weld on in the driveway all the time, but I always face the garage and have the RV on the lift of me and my other car on the right. So no one complains until I start grinding.