From my checks I can see all you need is the PNR and the surname to cancel the ticket on Lufthansa.com so the proof needed is far less than a telephone conversation where perhaps some more personal details would be needed. However, I'd imagine with access to email the only benefit would be a voice capture of who cancelled it, particularly if it was male and in this case the pax is female.

I have contacted the LH lurker here to see if they can help because I have got nowhere with the call centre who keep telling us to email CR but a response/resolution before Saturday is slim to zero. I have also reached out the social media lot.

The issue is, LH445 on Saturday 1 Nov is busy and is showing full Y only as of now and she was booked in Q.

This is a good lesson for all to ensure that you keep your PNR secret. A few weeks ago, the hacker could have cancelled around 5 tickets causing even more havoc and thousands of dollars in change fees and fare differences given LH's policy.