If you're referring to the pronunciation of the quick D (like a Brazilian short R), I believe you're correct. There are many different accents in the United Kingdom, so we cannot really talk about British English. What people usually mean by British English is the RP, but most people don't speak that way, even in southern England, where it originated.

Much of the differences amongst "accents " are related to cadence, not really the pronunciation of words, so in a song the cadence of a sentence is replaced with the melody of the song, and then you notice that in fact the words actually are pronounced the same. In fact many features of thought to be unique to a country's pronunciation are found in other English speaking countries, like for example the dropped "r" which very common in Britain and also Australia and New Zealand, but is also fairly common in America .