May have already sounded like that, my guess is at most, he hi-passed filtered a guitar sample which already had some distortion/tube amp thing on and just chopped it and re-sequenced it and HP filtered it a little.
If you were to try and use a synth, you'd get pretty close with something like Korg Legacy MS20, it does tend to have a bit of a guitar-ish overdrive thing if you set the filters right. Or even some additional guitar amp style plug-ins for efx or something.
Does sound like a guitar though to me as well.