If he was an agent from the start, I doubt we would have learned this much publicly. The materials would have been much more valuable to Russia as pressure points, compared to the public release (yes, of course they spinned it properly, US is watching you and they are hypocrites etc etc, but this was damage control and closure from their part).

As a Russian, I am not 100% convinced that US are evil imperialists [at least before 2025]. Have some humility, there are many more evil imperialists. You are probably not even in top 5.