Hi there group, would appreciate your advice on a damaged luggage issue

I flew on a code-share flight with Malaysia airlines and Oman air (ticket was through Oman air) from Australia to India (via KL then muscat)z The first leg was MH and next two was Oman Air. First flight (MH) which was delayed, I made it on the onward oman air flight but my bag didn't. Rather than putting it on the next oman air plane
MH decided to send the bag on another MH flight unaccompanied by me to my final destination. The bad arrived heavily damaged and needed replacement.

When lodged a baggage damage claim issue with oman air, they said Malaysia airlines is responsible as dealt with bag 100% of the journey and should compensate. MH said the ticket is code-share and therefore the predominant carrier (Oman air) is liable for the damages and compensation

I've not bothered claiming on travel insurance as the excess would basically be close the cost of buying a new bag outright and so didn't make sense

Who is at fault here and do I have ground to pursue compensation further? Both are blaming each other