The Dallas police used a ‘bomb robot’ to kill a shooting suspect. That’s a really big deal.
I'm not sure why it was a "big deal". The guy was allegedly given an opportunity to surrender, and kept shooting.
In other situations a police sniper might have taken him out, if they had a clear shot at him. How is a robot bomb legally different?
The guy had his chance to surrender, and he chose poorly. He made the decision to confront & defy deadly force directed against him, and he lost, in accordance with law. I consider this case closed regarding his death.
Now, as to whether robot-controlled bombs should be used in other situations, that depends on the circumstances. Same as the rules when you deploy a deadly police sniper. If you can use the one, you can use the other, in my view.
My main concern would be the safety of other people inside the same structure. A bomb, unlike a sniper's bullet, is rather indiscriminate.