Can't he simply tell them what he found out asap, and let them choose to risk an operation, seek help with healers, take time to earn some money to pay said healers with first, or take time to let ai get better at operating before taking an operation.
Sure, the latter two are unwise, but they are still options that should be brought forth alongside their disadvantages, and they are options.
Then I suppose there is the option of wasting away to death, that elf might prefer that over receiving treatment or help.