Oh it is! - from a distance, German and Dutch sound and look quite alike, and for that reason many Dutch people think they know how to actually speak in German as well - but one is bound to make terrible mistakes if one believes the languages are so much alike. A lot of words sound the same, but have totally different meanings...
Yes you're so right... I embarrassed myself at the football world cup where so many dutch people came to germany and we tried to talk
but it worked after a while^^