Seed phrase are vulnerable when store digitally so it is wise to creat many copy of it on paper and stored in a place that water can't reach  a recovery phrase Totally consist of 12 to 24 random words if I may say for me I adopted the act of splitting each words of my seed phrase and storing them in different locations that only I can remember while many person I know may prefer to store it in a dry container and kept in a place that has a good temperature  .
While that may have happened to your friend it is not be setting that after the repair of his phone his seed phrase will be gone or recovered but maybe there might be a slight chance for him I recommend he repair the phone first