When a writ of seizure and sale is executed against a debtor, how does the bailiff establish ownership of items that could be co-owned or bought by other family members staying in the residence. Do the debtor's spouse and children have any recourse against a wrongful seizure, even when they do not possess a proof of ownership of the items seized. Where does this burden of proof of the seized items lies when establishing claims?
No, nor could he seize goods belonging to a company owned by the debtor.
In general, it would be enough to state that the goods are the property (jointly or otherwise) of someone else. The onus of proof rests with the creditor,
An example of the process from New South Wales
In Germany, the Gerichtsvollzieher takes care of seizing goods, after being asked to do so by the creditor. During a seizure (Zwangsvollstreckung), the Gerichtsvollzieher is not required to check whether the goods actually belong to the debtor (since that would be impractical) - it's enough that they are in possession of the debtor.
However, if goods are seized that belong to a third party, the real owner has a right to get them back. To get them back, the third party must first ask the creditor (who had them seized) to give them back (if they sue right away, they may end up paying court fees (§93 ZPO)).
If the creditor refuses to return the goods (maybe they don't believe the third party), the third party must sue the creditor. This is called a Drittwiderspruchsklage (§771 ZPO). Then the court will decide who is right. The burden of proof in that case will follow the usual rules for civil suits, i.e. usually "preponderance of the evidence".
In practice, if the debtor or the spouse make a convincing argument that the goods are not the creditors property, the Gerichtsvollzieher will likely decide not to seize them, as doing so would only create extra work. However, that is up to them to decide, and they are actually required to seize goods unless it is "obvious" that they are not the debtor's property (§ 119 GVA).