The owl had gone for the base of the house, and Sirius didn't give a fuck for going through the house. Who knew what kind of shite a Death Eater cast on it. But hey, if there were no house left...or rather, since the bird implied basement, if there were another way in...then once they got Remus out the house could blow like a bunch of fireworks.
And they had gotten in. Tired of waiting - and waiting and waiting, as he saw it - Sirius ran right in and saw Remus in the corner. "Remus, oh thank Merlin, are you okay? You're going to be okay. We're rescuing you." And there was more he wanted to say, but Sirius ran over, giving Remus a small kiss on the forehead before focusing on the cuffs.