Around 0:32:33, when Clara is putting on makeup, she momentarily removes a part of the black wig and shows Helen Mirren's blonde hair. (Noted by Mirren in the "Helen Mirren Remembers" section of the "Helen Mirren at the BBC" DVD box, compiled in 2007.)
Several people walk through the "mud," yet nobody gets it stuck on their boots or shoes.
Around 0:36:30, Benito reminisces about a youthful experience in Romagna, a region in northern Italy. In the subtitles of the "Helen Mirren at the BBC" DVD box, this is transcribed as Romania, an Eastern European nation with no border on Italy.
One of the Italians is called Pedro, a Spanish name. The Italian version would be Pietro.