No mention of the last transmission being understood, only received in whole. (Although I agree with Flybymike's view.)
I think this idea that "Roger" meaning "received but not necessarily understood" is utter bolloks. How on earth can you acknowledge receipt of something if you didn't understand it? This argument is pandering to the modern pedantic culture of "Ah but you didn't exactly explain that to the exact nano letter".
Early during my training I acknowleged a transmission from A/G with "Roger". My instructor asked "What did he say?"--"Um, I'm not sure" "Then why did you say roger if you don't know?" Lesson learned.
edit:- By the way, I have a spaniel dog, it's a Cavalier King Charles 3 months old tricolour called Bruno. Just thought I'd mention that piece of trivia.