Well presume everything false till proven true. I know from what I have seen that Putin made this claim a while back, she might have even borrowed from his speech or perhaps they just came to the same conclusion. Unfortunately verifying everything is damn near a fools errand and extremely time consuming. Most things I see on both sides is bullshit, and most of the time people point to the other side's bullshit to avoid proper arguments. If you get too skeptical you wind up wastimg too much time digging for truth and never come to any conclusions, if your not skeptical enough you wind up believing anything. The healthy middle ground is learning what to question and what to not bother with and learning who to trust and to still have a bit of skepticism towards even them.