Actually, Steve it is worse than that. The particular straw grasped at is in favour of the EU and against the UK being separated.

before being identified in UK & Ireland

That's perhaps careless phrasing. The horsemeat was identified in Ireland (10 Dec 2012). The UK was not involved. Sample were then sent to Germany and Brussels labs - again the UK was not yet involved. Once the presence had been confirmed, the UK was informed on 14 Jan 2013. Whereupon it undertook the important but essentially drudge work of checking lots of products.

This is a good example of the EU working together, taking advantage of the fact that not everyone has to test everything, as long as the results are shared.

Now suppose we get to a no-deal. Have we strengthened the inspectorates so they can do all the testing of everything themselves now? No. The horse meat was being sold in the UK, but we were not detecting it. That didn't really matter too much if, as part of the EU, someone somewhere was testing it. From now on, it has to be us.

Or, of course, we can let the standards drop, in practice if not in law.