First of all - I would advise you against concluding anything out of your own analysis of the data, you need to consult someone with appropriate training!
Can you get both? The
.bam file is a format that stores information about sequencing reads (usually mapped, but not always). You can even extract the original sequencing information from bam files. This is practically the rawest information you can have. The
.vcf file is a variant file that gives you some information about inferred variants, but there are plenty of bits of information that will be missing. The basic information regarding sequencing depth and quality of variant calling is still included and therefore most likely sufficient for your physician to see any other variants potentially relevant to your friend's condition.
I will repeat once again - don't conclude anything on your own. It takes years to gain expertise in analysing genemics data and there is very high risk of misinterpretations if not analysed with care.