Theodore could honestly not be bothered with such a long winded way of finding out if Guilian was the guilty one or not. But he would not interfere if it was Dolohov's intention to go down that route.
'Since your contacts on the continent are better than mine, perhaps you could arrange for something like that?' he asked. In any normal situation he would be the one to find things out, to keep on top of things, but at the moment, he couldn't be bothered. He wanted today to be over so that he could take Padma's remains back to Nott manor and say good bye on his own, without all the people around. Then he wanted to focus on getting revenge. On Lisa for killing his wife, but he now had a reason for this war to be over as soon as possible.
It was time to use Rodolphus' secrets against him.