There is almost impossible that explosives damaged Nord Streams NS 1 and NS 2 because of an accident. If the gas pipes are buried in the bottom of the sea. That thing means that the makers of that thing should dig those pipelines to the surface so that they can put explosives around them. And there should be some kind of marks at the bottom of the sea if those operators use submarines. Or some kind of surface vessel that can support the operation. But there is a simpler way to detonate a couple of gas pipes. The operators must just get access to the pumping station. And then send the robot to travel in the tube. The robot that is made for detecting damages inside the tube can easily transform to carry explosives. Some of those welding robots can carry explosives. They made for the thing called detonation welding. In those cases, the underwater robot simply detonates the muffle joints in one piece. The detonation happens by using explosives that are pressing...
For finding solutions for problems, we must not claim that some proposition is right or wrong. All possibilities are open. Until they are proven right or wrong using empiric methods that are scientifically accepted.