I think that in a way, Anybodys behaved worse than the rest of the Jets when she said, sarcastically and nastily "Bernardo's girl wants to help." Then, when Action said "Even a greaseball's got feelings.", Anybodys said, rather accusingly "But she wants to help get Tony", that helped set Tony up to be killed, first because Anybodys, in her own way, kind of instigated the assault on Anita by both her sarcastic "Bernardo's girl wants to help?" comment, and her accusing Anita of wanting to help get Tony.
In retaliation, Anita changed her message, and that was the catalyst that led to Tony's death. It was Anybodys who caused Tony's death by her sarcasm and her accusations towards Anita.

I think until the rumble, everything was a game for these kids from gangs/rumbles to being in love. I think even after the reality of death starts to sink in, there is a desperation to continue "the game", as if it can somehow erase grim reality. I think that's the reason Tony and Maria think they can get away, and part of the reason for the attempted rape of Anita. Anita seems to be the one young person able to see that life isn't a game. She is genuinely afraid for Bernardo, Tony, and Maria.

When one is in mourning, they do not think of what they say. It just blurts out. Anita would have been justifiably furious, knowing that the killer of the man she loved had just slept with his sister, and in a family like that, it would be like spitting on the corpse. Perhaps, too, at this point, Anita did not realize that Bernardo had killed Riff, even as an accident. The emotions at this point are so high that she's not thinking realistically, just as she changes after she is assaulted at the drug store. "Bernardo's girl wants to help!" I find the assault on her to be totally vile, but had they allowed her to speak to Tony even standing between the two, they would have prevented Tony's death. That's the power of "West Side Story" is that it takes you into areas of anger and violence that we try to suppress in ourselves and often implode when it takes over our hearts and brains.
"Great theater makes you smile. Outstanding theater may make you weep."

To be fair, I think Bernardo killed Riff by accident. You could tell by the surprise on his face
To be honest, I'm not so sure that was totally true. Second-degree murder (which means a little bit of both accidentally and on purpose.), but they'd all done their share of killing, and, in the end, they also got killed.

To be fair, I think Bernardo killed Riff by accident. You could tell by the surprise on his face

Also -"Wants one thing only". I doubt if Anita was a virgin!

Actually, come to think of it, I have, on occasion, thought about the irony of Anita angrily berating Maria for loving Tony, who'd killed Bernardo,(who was Maria's brother and Anita's lover.), because Anita, too, loved a guy who street-fought and killed (He killed Riff.) It seems like Tony, Riff and Bernardo (all of who ended up going down for the final count.), had assaulted, been assaulted, and had killed.) Bernardo, Riff and Tony were all more alike than they wanted to realize.
Anita and Maria also had something else in common: They both fell in love with guys who'd street-fought and killed.