Well I just tested and (at least on Nuclear Dawn) players will be logged during map change when disconnecting on their own or for failing to download files or what have you.
You can tell from this example that I disconnected 2 seconds after map change. Here I set cl_allowdownload 0 on my client and changed my server to a custom map:
Code:
15:19:59 - <Xander> <STEAM_1:0:XXXX> <108.XXX.XXX.XXX> CONNECTED from <Unknown>
15:20:34 - ===== Map change to sk_plaza =====
15:20:36 - <Xander> <STEAM_1:0:XXXX> <108.XXX.XXX.XXX> DISCONNECTED after -1 minutes. <Disconnect by user.>
I assumed these
generic server events are the same across all mods, but perhaps they aren't. What game are you running?