We should give them the benefit of doubt about this particular accusation because the people accusing them 1. Have not presented evidence, merely asserted some

We should give them the benefit of doubt about this particular accusation because the people accusing them 1. Have not presented evidence, merely asserted something and demand to be trusted 2. Have a long history of lying, and clearly feel they are entitled to lie to you when they feel it's useful. There are plenty of times you should not give the Russian government the benefit of doubt, but it's the other side which is making a positive assertion here.