The Angel of San Bernardino - S3-E20
Other mistake: Lucifer's obsession with Bones is highlighted here when he confronts someone as a killer only to realise it's because he's an actor who played a killer in the Bones episode Intern in the Incinerator (a role Scott Rinker did play in real life). Kevin Alejandro (Dan) and Aimee Garcia (Ella) also played roles in Bones, which Lucifer never comments on. In fact so did Jeremiah Birkett (Lee Garner, "Mr. Said Out Bitch").
Answer: As Cain theorises in a later episode, it's Chloe's love, not presence. This early on, Chloe had no strong feelings for Lucifer, so had no effect on his immortality. In fact even more recently he's back to being invulnerable around her after speculation that he chose to let himself be vulnerable. So while there's a degree of flexibility / retconning going on, it's all explained in-show.
Jon Sandys ★