I don't know what your opinion was on the matter. For me, Angel had no business ordering Lorne to murder Lindsey. He had no right to do this. Not only is a douche in my eyes, but even more of a murderer.
Officers in armies have given orders to kill for all of recorded human history. At least Angel asked for volunteers and didn't draft his army. Now, from Power Play:
You didn't judge. You didn't spend your life obsessed with good and evil. You do that, you get swallowed, lost in the minutia. Good, bad, Angel, Angelus"” None of it makes a difference.
And so Lorne was "swallowed", as he went from his role as storykeeper on the periphery, above the "minutia", to active participant [or if you prefer, he went from historian to a participant in history]. And, yes, he couldn't reconcile himself to notion of active participant and so he bagged out, and no surprise that our end has the final line, with Lorne absent, let's go to work...
By the way, you should have seen this coming with the destruction of Caritas. In the narrative, Caritas functioned as the one place where all engaged in the struggle over "good and evil" could go for an escape (where one didn't judge or obsess over good and evil). Except the escape was a lie. Just as is Lorne's pacifism. To borrow from George Orwell aka Eric Blair [the one premise that the pacifist can never accept lest cognitive dissonance set in]: Those who "˜abjure' violence can only do so because others are committing violence on their behalf. And what were you expecting? Buffy killed, Willow killed, Xander killed, Anya killed, Giles killed, Dawn killed, Potentials killed, Faith killed, Angel killed, Wes killed, Gunn killed, Fred-Illyria killed, Cordelia killed, Conor killed, in other words, everyone who well and truly cared that good triumphs over evil, killed. And don't know whether Joss intended such, but what Lorne always was is made painfully clear in the end, to wit, anti-hero. The survivors take on the world's evil in that alley, and where's Lorne? Not there, because he tells Lindsey that such line of work is "unsavory" (morally disreputable). And so anti-hero. For one more, even Illyria transformed, but in the other direction. She goes from Wes being one of the "Motes of dust. Mayflies who die so soon after they're born they might as well not live at all", to, "I'm feeling grief for him. I can't seem to control it. I wish to do more violence."