A word of warning:
Some people may remember my posts about my dd, who was similar to yours at 12. Eating sweets and crisps secretly and hiding the wrappers. Aggressive - physically and verbally, bullying to her siblings, no hobbies, very confrontational and argumentative. Spending all her time at home in her room.
I posted at length on this board over several years and got a lot of support and advice not to engage, set firm boundaries, keep talking etc. I followed some of it some of the time, but found it very difficult to stay calm, not engage etc, mainly because of how long this went on for, and also that it escalated - we all got so worn down by it, and it has had very negative effects on one of my other children's emotional well-being.
FAst forward a few years, she is now 16 and has just been assessed by a specialist team at a top London hospital, where she was referred by CAMHS. She's been diagnosed with conduct disorder, PTSD, body dysmorphia, treatment resistant depression, a lack of empathy, and possibly a personality disorder (question mark over this - will reassess when she has had treatment for the PTSD, depression and body dysmorphia).
. Things are not all desperate. She's no longer aggressive to us, is attending college regularly and doing well on her course, our relationship is good now, and things are incomparably better at home. But the whole family has been damaged by the experience of those dark years, and dd too. The discord at home resulted in her engaging in risky behaviours away from the family, damaged her relationship with her siblings, damaged my physical and emotional health, and nearly broke our family apart altogether (this time last year I was looking for flats to move into with my two other children, leaving dd with DH as he had the less fraught relationship with her - no problems with our marriage, but just felt that living together as a family wasn't feasible with dd being as difficult as she was).
Anyway, sorry to ramble on. I didn't mean to hijack your thread. I think what I wanted to say was that sometimes really awful, difficult behaviour isn't just at one end of the spectrum of normal teen behaviour, it's a sign of significant emotional and psychiatric disorder, and may have serious and long term sequalae for the child and for the family if it's not recognised and treated in a timely way. If you feel that something is not right with your dd (and repeated violent outbursts from a 13 year old are pretty extreme IMO) then I would pursue it and raise it with your GP. I'd also encourage your partner to consider whether this might be something more than simply inconsiderate and selfish behaviour by a stroppy teen, and adapt HIS behaviour accordingly (ie, not guilt-tripping, shouting back etc)....