> It's more concerning that Congress is that stupid
Congress was looking at evidence of what that particular user was doing online at the time, because /u/stonetear posted questions that look rather incriminating in retrospect based on what we've learned since then.
This kind of thing is why it's important to establish a chain of custody for evidence.
Maybe. It depends on what internal controls they have (or don't) and whether it was evident to other admins that the comments had been altered.
There's a lot we don't know without knowing the internal workings of Reddit, though I agree that you can't have to think that if one rogue person (even someone like that) can just do such things, they don't have robust internal controls at all.
Congress was looking at evidence of what that particular user was doing online at the time, because /u/stonetear posted questions that look rather incriminating in retrospect based on what we've learned since then.
This kind of thing is why it's important to establish a chain of custody for evidence.