I am just reading Josef Zaluski's memoirs. He served in the Polish Light Horse of the Guard. After the fall of Madrid in December 1808 he has the following to say:
"Close to this town [Tordesillas] our regiment was directed to the left to observe the movements of the English army which Napoleon was already pursuing. Here we had a test against the English cavalry, which consisted mostly of Hanoverians, close to the village of Servinianos. From this village I was sent on patrol by the adjutant Major Duvivier with a platoon from the 5th Company, and was led into an English ambush by a Spanish guide. Having split my platoon into two units, the first one I sent to the right under the command of Sergeant [Józef] Waligórski, newly decorated with the Legion of Honour for having captured a flag at Somosierra, whilst the second one I sent a little to the left, having under me a Sergeant Wojnarowski, not yet decorated, but an old soldier. Soon we were attacked and chased back by superior English forces. In the confusion, young [Roch] Rzuchowski, brother of the famous colonel of Krakus Horse, had his saddle slip off his horse. It was almost a miracle that I with Wojnarowski managed to save this young man from English captivity. Then Squadron Commander Tomasz Łubieński and Captain [Seweryn] Fredro came to our rescue and repulsed the English horse, though Captain Fredro was wounded by an English sword, and Private [Michał] Żwan was taken captive by the English."
Is this skirmish ever mentioned by British eyewitnesses?
Depending on who is making the statement, such as the French, it was. Comments should be taken in the context of the times, and by who is saying it-not is what is accurate or not in the early 21st century.