I wanted to warn you about the HL2DM server you were connected to.
It is called Fastpath.
They are scammers and create about 80+ fake servers daily on the hl2dm list and other games. They are killing the real HL2DM servers slowly.
They steal server names and player names.
They also steal you Steam Auth ticket for up to 5 days.
The way to revoke it is to connect to a legitimate hl2dm server. Any will do.
If you like you can download the blacklist on https://gamebanana.com/mods/289337

ggs