This have not happened to me before, so I cant say for sure. I don't think the seller can remove the strike. But you should contact the seller and explain what's going on. Because I don't think he knows about this strike. I think the seller could get rid of it if he contact ebay and say you have paid even though you havent payed anything yet. But I don't think he would want to do that. But then again if the items not been shipped, it could work.
The right way to go about this is to contact ebay. And hear what they say about this.