TrustedHouseSitters did not change anything after reviewing the unanimous views from the forum (petowners and sitters) that clause was 5.3.5 is unfair and unenforceable.
After weeks of reviewing it their decision was the clause will remain in as someone has to pay . Direct quote from their response 
And when asked about what provisions are in place to support a sitter if the homeowner does not reimburse the sitter for charges paid their response was
The above experience demonstrates that the well thought out , reasonable, clearly articulated and carefully considered views of the forum members do not hold any weight with the THS decision makers . I understand that not all forum members are actually THS members so maybe if members individually take the time to write about these absurd clause to THS they may be persuaded to take our concerns more seriously?
Currently under the TOC If the home gets damaged in a storm and a pet gets injured ; and the home owner cannot be contacted according to these clauses the unpaid sitter must fund all the emergency repairs and vet fees !!!
Then if Home owner does not reimburse the unpaidsitter, the sitter will have to take legal action at their own expense to get the money back .