Why is Brian Doyle Murray a coward?

In the Arrested Development episode "Missing Kitty" (S01E16) Tobias, during his in-prison research for the role of "Frightened Inmate #2", is having difficulties with his new roommate White Power Bill. But when he approaches the Warden with his fears, he manages to convince Tobias of going on:

Warden: But didn't you come here to research the nature of fear? I can't think about a better teacher than White Power Bill, he's like a master's course unto himself.
Tobias: So you think I'm a coward?
Warden: There's only one man I thought to call a coward, that's Brian Doyle Murray...No, what I'm calling you...is a television actor.

But I didn't get the reference to Brian Doyle Murray. Who is this and why does the Warden call him a coward? It seems unlikely for the show to just pick any arbitrary name without any relevance to it. Seeing that there is a famous actor named thus still doesn't help me to understand his relation to Arrested Development. Or maybe it is a reference to some casting related quarrels between the show and the actor (as Arrested Development indeed sometimes references incidents related to the show's production itself)?

Best Answer

There is no discernible reason... which is why it's funny.

A bit of background: The warden is played by James Lipton, founder of the Actors Studio Drama School and host of Inside the Actors Studio, where he's been interviewing over 200 stars for more than 20 years. That show also made him somewhat of a cult figure due to his odd affectations and tendency to glorify his guests regardless of their accomplishments, which was the subject of numerous parodies - one, coincidentally, by his Arrested Development co-star David Cross.

So this makes the line a funny non-sequitor for several reasons:

James Lipton is highly unlikely to call any actor a coward;
We'd expect him to name-drop big stars, not Bill Murray's less known, character actor brother;
Calling Brian Doyle-Murray that, of all people, is surprising because he's an affable guy who mostly appears in comedies;
After a bit of research, there doesn't even seem to be any connection between them, so the joke suggests a mysterious, hitherto unknown bad blood between two amusing figures who aren't really perceived as aggressive.

The joke wouldn't really work (or be less quirky or clever) if he'd mention a well known celebrity or someone who's maligned or known for being cowardly. It's an example of the surreal little moments (and off the wall references and off-beat casting) that made Arrested Development so special.