We do not yet know how Tsad Kadima in Jerusalem awards its qualifications. In all cases, as you would when considering any applicant for a post, ask to see copies of the relevant documents to assure yourself that everything is above board. In this world nothing can be said to be certain, except death and taxes. Their purpose is to prevent individuals working abroad from having to pay tax on their foreign salary both in their own country and in the one in which they are working. According to the terms of the particular agreement between the two countries involved, the tax will be paid in one only.
Many Hungarian conductors work outside Hungary.
If you wish to employ a conductor from Hungary, the UK or Israel, then you should check whether your own country has a relevant double-taxation agreement. Remember Benjamin Franklin's warning. Double-taxation agreements are bilateral, that is they are negotiated and agreed specifically between the two governments involved. No two agreements, therefore, will be the same. The basic rule everywhere is to find your own relevant regulations and follow them.