Need help with figuring out the reason for crash on the first test flight on a new build. [Link to log file included]

So we are trying out a new build, 22inch props, 170KV motors, 12s battery, custom, coaxial-H frame with 2 motors on each end. Today was our maiden flight with this build and we were planning to tune it today.
Unfortunately, we ended up crashing it. Checking the logs tell us that the P-gains we started were high and the fact that a lot of tuning needs to be done. That still doesn’t explain the crash at the end or the spike in vibration at the end. We found some damage on post-crash check, but we are not sure whether it was a mechanical failure that led to the crash or the other way around. We’re new to the PX4 ecosystem so are still in the process of figuring things out. Any help is appreciated. Logs can be found at: