Sanford was all by himself and killed 3 agents; He got stabbed, but then used the RPG on the Agents and he was too near. He had a short time to live by talking to Deimos.

Here's the dialogue of The last part of Dedmotation:

Deimos: Sanford! You okay pal?

Sanford: I'm not Deimos...I have only a bit of time left to live....

Deimos: Don't die on me Sanford! The Dissenter can revive you!

Sanford: I'm sorry Deimos.....

Sanford: You were my best friend at all.

*Sanford dies*

Deimos: No!