Yeah, landing on the roller (or the spring in my "cheap home made car spring/skateboard with no trucks combo" case) hurts something fierce, good thing I was drunk at the time
Had a wicked bruise for about 2 weeks, I find once you feel yourself going it's better to just jump off rather than try to go for the save.
Haven't ridden mine in a while... the skateboard has started to delaminate, was only about $15 though so I'll pick up another one sometime...
I might change the car spring to some 150mm (6") PVC piping if I can find end caps for it as well, without them the PVC bends too much and will crack after a while. I also want to half fill it with sand or something to slow it down if I need to.
Obviously my home made one isn't the same as a real Indo Board, but it has helped my balance I think, especially riding switch, plus you can practice any time you want without needing to find a third rider or get the boat out.