Doesn't the "creation model" have a firmament over the Earth, with stars fixed to it. How did the water, mud and rock pass through that? Or is Mars also fixed to the firmament?
Seeing as how powerful man, with powerful rockets, hasn't reached further than the Moon, OF COURSE a slush of water mud and rock just escaped into space and splattered onto Mars.
It's not a stretch in the same way as thinking that unicorns have earrings. The second part isn't that strange, really (neither earrings nor microbes with mud are that uncommon), it's just that the first part (unicorns existing and mud splattering onto Mars) is so completely and utterly ridiculous and impossible, that makes it all a stretch.