Mr. Monk is the Best Man - S8-E13
Randy Disher: I think somebody's trying to scare you.
Captain Stottlemeyer: Yeah, but why? I mean, it doesn't track. If the guy wants a piece of me, if he wants to hurt me, why doesn't he come at me? What's all this cat and mouse crap?
Disher: So who's on your short list?
Stottlemeyer: I've been at this all morning. Most of these guys are either in jail or dead.
Disher: Or both.
Stottlemeyer: No. Nobody is both.
Answer: Stottlemeyer was already upset after the phone call. He was trying to get "Kevin" (who would have to be a judge, but no further character information is given) to issue a restraining order with no evidence of needing one, except that Adrian Monk said she needs one. Kevin said he would need to "sleep on it." So it's clear they've been trying to provide protection and unable to get the results they need, which seems to be based on no one trusting Monk the way Stottlemeyer does. He's just angry that they failed to protect Linda despite all their work. Although it does feel like a scene was cut, or altered, from the show that shows the futile attempts to protect Linda which built up to his outrage.
Bishop73