Why do the rail shots look totally off when I spectate?
When you play the game with lag compensation on, your hitscan attacks are predicted. Even though they haven’t really happened yet (your commands need to get to the server before they’ll happen), your game shows you what probably will happen. Things look generally consistent. When you spectate another player who’s playing with lag compensation on, you see pretty much exactly what’s happening on the server. The server does hit tests based on where the attacker saw his potential targets, rather than where they are. That means, for a positive hit test, the rail shaft will be drawn through where the hit target used to be. You’ll see the rail shaft at that position, and the target at his new position. There will be a discrepancy, and the rail trial may look like it actually missed. That’s it. There’s no cheating going on, no weirdness – just a visual inconsistency that it’s impossible to get rid of without creating inconsistency of other types.
