All officials in the UK tax department frequently appear to give conflicting advice. Foreign crews as well as visiting foreign businessmen do NOT have to declare income and pay tax. Unless there are other circumstances, this is the case. I assume you are a foreign taxpayer domiciled abroad? If not, then your question was misleading. A potential liability has been declared in order to be able tax people working out of Britain if they are foreign taxpayers- thus British crews living abroad can be taxed on the British income whilst within British boundaries. The intention is not to tax foreigners visiting on business trips as long as they are taxpayers abroad.
This post would be better in the Questions Forum- this is Rumours & News.