Original sentence: At the time, there is some confusion over Allen's nationality as he was living in Australia at the time and some Everest organizations listed him as being Australian.Following the ascent and subsequent death of the 22 year old Briton Michael Matthews in 1999, Grylls amended his claim to: "the youngest Briton to summit and return alive".However, this claim is controversial as it later transpired that Grylls may not have been the youngest Briton to climb Mt Everest
Edited sentence: At the time, there may have been some confusion over Allen's nationality as he was living in Australia at the time and some Everest organizations listed him incorrectly as being Australian.Following the ascent and subsequent death of the 22-year-old Briton Michael Matthews in 1999, Grylls amended his claim to: "the youngest Briton to summit and return alive".However, the claim is controversial as it later transpired that Grylls may not have been the youngest Briton to climb Mt Everest