The ping on the scoreboard isn't always correct. Where sometimes my ping on the net graph is something around 100, on the scoreboard, everyone will be up around 900s and not be experiencing any more lag than usual.
The ping actually is a lie in every Source based mod I've played. It's much much lower than in net graph(which I take it is the real ping time). There could be a bug somewhere there as well, but Source shows wrong pings on scoreboard anyways.
I get useful ping values in scoreboard in other mods (also in emp 1.07). The value in scoreboard is average ping from last few minutes so you can get lag spike then it will get higher on scoreboard and after lag disappeared you will see scoreboard showing more than net_graph.
Yeah scoreboard is average. But I think there is something to do with server update rates that can cause it to show a wrong ping.
Well, to me the scoreboard seems pretty accurate. In any case, it shouldn't matter as lonag as the server isn't lagging.