no problema. Asymmetrical airplanes are unusual but not unheard of; there are several German examples from WWII as well. The asymmetry is typically used to offset engine thrust, which is really not an issue in surfboards. There are many asymmetrical sailboats as well, e.g. high speed sailboats, outrigger hulls - again, though, this is used to offset an asymmetrical force (wind from one direction only). here’s some examples: http://www.schachtdesign.com/proafile/primer.html
I think both you and Jim are right; asymmetry is a design feature that shouldn’t be used unintentionally, but only when there is a reason to plan for it (as opposed to a lack of craftsmanship)…