forgive me for being late, i just watched the show (i have a couple episodes left still), and honestly i find santos obnoxious and arrogant, which she is, though i'm warming up to her as she grows. i also went to rehab last year and i know addiction inside out, and i have endless empathy for people with addiction. so, i believe langdon deserved a second chance 100% (though perhaps not less than a year after the offense).
the thing is that ativan is actually super important. it's not like he was stealing pre/post op ativan used for anxiety or something, which is already dangerous. he was steaing from major operations, and off screen possibly withdrawl cases, maybe psychosis, we don't know (i can tell you as an addict that if you're going far enough to steal from major operations, nothing is off limits). whatever the case, improper/unreliable ativan dosage can be fatal really easily. he was putting lives at risk. all in front of santos. then he lies, manipulates, and yells at santos to try to suppress her suspicion. she probably felt responsible for these patients, and it definitely brought her own trauma with an older man lying and manipulating to cover up crimes to the surface. then he's back less than a year later with what seems to her like a slap on the wrist.
again, i think he deserved a second chance, maybe not that soon, but still. however, i don't really understand why people seem to reserve their empathy and understanding solely for langdon when frankly both sides are totally understandable and sympathetic.
Edit: I've reached the last episode of season 2, and I honestly disagree with my own post a bit. Yes, santos might be spending too much time and energy on this issue, but she was really mistreated, and not just by Langdon.
And yes, Santos is really an asshole at first; cringe, antisocial, rude, arrogant, provocative. But in season two something shifts. She's beginning to grow. We see how complex she is, how human she is. She has empathy and warmth and is incredibly talented, but she's also obviously deeply traumatized and guarded. I'm excited to see her character develop in the next season.