That little mini-episode was such a sweet holiday treat.  

Thank you. I didn't know there was a minisode. Are there more?
 

I didn't see the xmas episode but I've always found Anderson's 180 degree turn around to be a bit unbelievable/unrealistic. Donovan was just as involved with the stuff that he's guilty over and yet she hasn't gone mad. Also if the guilt caused his turn around then Sherlock's return should alleviate some of the obsession he's shown toward Sherlock during Sherlock's "death" but his obsession doesn't change. Throughout season 3 he is as dedicated to The Empty Hearse society as he was before Sherlock's return. His obsession actually seems to have intensified as he admits to stalking Sherlock in His Last Vow.

I definitely prefer the old Anderson to the changed one. Though I guess I can see some of the reasons put forward for his change are not totally unbelievable.

I like the new Anderson and find it funny that he's now essentially become the leader of the Sherlock fandom (within the show world). Guilt affects people in very different ways and I think Donovan always disliked Sherlock more than Anderson did. She was the ring leader in doubting him and bringing it to the attention of Lestrade. Anderson just went along with it, possibly because he was sleeping with her.

You could even argue that Anderson's bitterness towards Sherlock in the first two series came from his jealousy/admiration of his amazing skills, so I think it does make sense as a character development.

I liked the new Anderson, too. All that vitriol aimed at him was initially funny, but it became tiring with time.
 
I also don′t think Anderson′s turn to Sherlock′s supporter was that unbelievable. It seems to me Anderson was mostly annoyed with Sherlock for professional reasons – Anderson as a forensic expert couldn′t stand Sherlock′s total disregard for regulations governing the crime scenes they were investigating. The way Sherlock danced through those crime scenes without proper protective suit, not wearing shoe-pads and sometimes even touching the crime material with bare hands, was certainly hugely annoying for a person forced to follow those rules rigorously. Still, it was not a kind of hatred able to outlast the shock caused by Sherlock′s apparent suicide.
 
(Anderson, a forensic expert, could also be the first person who realized Sherlock was actually innocent of the crimes he was accused of commiting. Forensics Anderson participated in did not lie – as he was retroactively investigating his old cases, he had to realize Sherlock couldn′t have messed with so much evidence.)
 
Donovan, on the other hand, was a different matter.
 
Donovan was painfully aware of Sherlock′s real abilities. The way he first deduced the existence of that pink suitcase in ASiP and then produced the said pink suitcase in no time was proof enough that he really can do what he claimed to do. He left no doubt for Donovan that he was a genius.
 
Why did she hate him so much, then? Calling him a “freak” and a “psychopath”?
 
In my opinion, Donovan′s hatred was the hatred of a mediocre person forced to acknowledge her own mediocrity. Donovan was a professional and a hard worker so it was painful for her to admit she would never be able to rise to Sherlock′s level. She ought to think it was unfair that Sherlock was born with the gift she could not top with all her effort. Moreover, Sherlock was childish, arrogant and irresponsible, as geniuses often are. Donovan had to be furious when she observed how that awful man (who was certainly “unworthy” of his gift, in her eyes) belittled her and the rest of her team.
 
In other words, Donovan was “Salieri” to Sherlock′s “Mozart”.
 
https://www.youtube.com/watch?v=-ciFTP_KRy4
 
Her hatred was much stronger than Anderson′s and it certainly influenced Anderson when they were intimate.
 

I partly agree with nakahara. For me, Anderson's (and Donovan's) attitude was mostly about Sherlock breaking the rules, walking through crime scenes without proper uniform and touching everything. Sherlock was never an official police cunsultant so if anything happened, the whole crew would be responsible for that: Lestrade for letting Sherlock be there and everyone else for not reporting it. I love and admire Lestrade's motivation but I understand why Anderson and Donowan weren't happy about Sherlock walking through crime scenes. 

Also, while Anderson was more like "nobody can be so clever" and tried to prove Sherlock was cheating ("somebody told you that") or his deductions were useless ("so we can read her emails, so what?"), Donovan saw in him the part represented by Moriarty. She noticed how happy he was when someone got murdered and it was freaking her out. Anderson didn't believe Sherlock's a genius and Donovan believed he's dangerous. It makes sense it was Anderson who, after many hours spent on analizing Sherlock's methods, became his greatest fan. I wish they showed us scene with Sherlock and Donovan in season 3 so they wouldn't fight and insult each other anymore.  

 

I think Vinette plays Sally really well, given what little she has to work with. She makes sure that her character never feels flat, Sally just seems to try to do the best thing. I never got the feeling that it was personal for her. Actually, the way she responds would be a normal response to someone like Sherlock, of course she doesn't trust him, he's a genius with an obsession for murder. Lestrade is the strange one, he's seen something in him that others haven't.