It sounds to me like he's excusing it on the grounds that a court in the US found it legal after a discussion of US and UK law, and the UK courts have yet to express an opinion. So 'should be legal' is accurate only in the sense that they think it probably is legal but there's no direct authority. It would be inaccurate if you meant 'should' as in isn't but should be.
See e.g. Shuey v US for an occasion where not only has a US court considered an issue of common law that's equally applicable in the UK and US first (contract in that case, but whatever), but has done so sufficiently convincingly that it's often cited here in the UK with a similar authority to genuine legal precedent.