Just spoken to Amex and referred to those terms, the agent appears to be interpreting that as meaning Sectoon 1.5 is covered in the UK, but as the personal injury cover directs you to another section (1.7) this is not part of the benefits under the car rental section (1.5). Not sure I believe that - is that your interpretation of the terms too?
Seems odd that section 1.5 explicitly mentions personal injury as a benefit but then because it refers you to another section it doesn't apply unless you also qualify for that section.