Grammar is our retribution. You are welcome. 
I am not sure why you both are fighting, though. I mean, a lot of English natives in this forums brought it up several times that they consider German hard. Yet I never saw a single German native making a similar statement in regards to English.
The Foreign Service Institute made the observation over a long period of time with a lot of people, that German takes a considerable longer time to learn than other germanic languages. Of course, the training is somewhat specialized, but still it stands out a bit.
So whether this comes down to lexical differences, the grammar or other factors not directly associated with the language, the empirical effect is clear: Native English speakers will in average need more time to learn German compared to other germanic or romance languages.