The Consumer Protection Act is clear that the importer is responsible for the product liability, however, it does include an exclusion from liability where:
the product was not supplied in the course of a business, for example, the donation of homemade toys for sale at the occasional church bazaar or sales by private individuals of second-hand goods;
(source - http://www.bis.gov.uk/files/file22866.pdf)
This would imply that individuals involved in personal imports would not be liable when they subsequently sell the items on after use. It may even absolve them completely But I would take professional legal advice though!
As a side note, next time you moan about the cost of RC products in the UK, please bear in mind that distributors such as CML for example have to pay for Product Liability insurance, as the responsibility lies with the importers not the manufacturers (outside of the EU).