That is not the opposite, they are referring to different time periods
21-28 trade at original price (with due bill)
31st in US accounts: you have 5x the shares at 1/5 the price
31st in UK account, 1x the shares at 1/5 the price (due bills not paid and no longer attached to shares)
Sept 3 in UK account: Additional 4x shares added to account (based on close Aug 28 count, due bill now paid)
Wow, libel much? How about this for a less nefarious option: The UK broker is not a stockholder of record for TSLA and is working through a (probably) US intermediary. That would add an additional step of transferring new shares from the US to the UK firm.
From their FAQ (emphasis mine):
Corporate actions - Frequently asked questions
See also the non-US members who don't get to vote.