Can this Buddhist do this job?

At my university I and my group were offered a case of opinion on Buddhism. Neither I nor my colleagues are Buddhists so we have done a lot of research in the last few days, but we are afraid of misinterpreted this religion. The case given to us is about a Buddhist who works in an investment fund and basically his job is to recommend investments to clients. Right now, the best investment he can recommend is related to the manufacture and exchange of automatic weapons. We found that having a job that causes suffering to other creatures is against buddhism and for that reason, since weapons are something that is created to cause suffering the worker is in doubt... Can he recommend this investment on weapon to his clients because recommending this investment is really far from causing suffering to other creature with a gun or it doesn't matter and it is against the buddhism and he should leave this job ? Thank you, Tiago from Portugal