Under the Financial Services Act, the term 'expert investor' actually has legal weight.
It is taken to denote an investor who, by his or her previous pattern of dealings, may be taken by a member of the Securities & Futures Authority ( SFA ) to understand fully the nature of the investment he or she is making.
What it boils down to is that if you're taken to be an expert investor, it is down to you to assess the risks involved with any given investment you may be offered.