You don't have to be at a company at literally the moment of inception in order to be classified as a founder. Basically, did he invest key talent and resources

You don't have to be at a company at literally the moment of inception in order to be classified as a founder. Basically, did he invest key talent and resources early in the company's lifespan, before it hit product-market fit? Yes. Infogami (Aaron's company) merged with Reddit 6 months in. Reddit was still largely unknown when infogami merged with it in 2005. Swartz was given equal shares so clearly Ohanian and Huffman valued this merger highly.