Argh. We've had to explain this to our own HL2DM team, too.
This "deathmatch" is a CODE BASE and is not a working DM mode. Players do not respawn, you do not have a player model (a decent one, anyhow), weapons aren't functioning properly, and they are held at...interesting locations.
We're coding an actual working version of DM with HL2DM - Wait a while and you'll have a decent DM mode.