I'm not a financial expert but I have been told by someone who knows a lot more than me that it would be very difficult for a parent company to simply allow a wholly owned subsiduary to simply declare insolvency and cease trading. They would be liable for any monies owed and, more importantly, it would have a significant impact on the credit worthiness of other parts of the LH business.
Unfortunately it is very easy for a company to let a subsidary go bust and because of Limited Liability there is no comeback on the parent company other than for direct cross company guarantees and I reckon LH would have minimised these well in advance.
Sadly its all too commonplace and generally companies planning this would have the major assets held in another company name with a contract between companies.