yet...somehow, it feels wrong to kill a player when he’s not there to see it go down...
This is a great thing to talk about in a Session Zero - what is the table's policy on absent players?
am I over thinking this?
How should I break the news to this player?
should I fudge something?
man I wrong to feel like a jerk?
Am I a jerk?
It should have been (and probably still is) easy enough to address.
You said the hungry goblins would eat the PC. Sure. But not right that second. There were adventurers about! You don't stop to have lunch when the enemy (or yoru second course in the meal) is right around the corner.
So, the ettins and goblins down the PC - but they aren't dead. They are captured, and hauled off and left for later. The rest of the party can rescue them later.