It depends.
If it is his CV, then it is up to him how he displays the information. I'd warn about putting things that arent true, but most employers will look no further than grades.
If he is filling a form out, then if the form asks for exams and dates, he should put those, It varies as to how detailed the forms are.
He will have one chance to resit his A levels on the existing legacy spec in 2017.
Think carefully about the ongoing workload and whether it might interfere with Uni. His degree will matter more, but first year counts the least.
In any event he has extenuating circumstances.
A levels tend to matter most as a passport to get you into Uni. They matter much less if he gets a good degree. For some graduate jobs, they are taken into account, but again he has extenuating circs. If he's interested in a known career then he chan check to see how relevant they might be.
So my answer is less about whether employers can see them (answered above), but whether he cna cope with the additional workload and it doesnt interfere with Uni. They could adopt a more cautious approach and delay Uni, resit the exams and go in 2018. That might be a bit much considering they have unconditional, but it might give them more time to deal with their depression. The degree grade will be much more important.