Not the first time that the words 'upload' and 'download' cause problems for posters and respondents to posters. I 'download' programs sometimes from the web to my PC, but the arduino developers decided to use the word 'upload' as the process to move a program from the PC to an attached arduino board. The words upload and download don't intrinsically define the direction of data flow, just as the words send data and receive data for a serial link doesn't explicitly explain the flow direction as both end nodes have the ability to send and rec, just on different pins.
I've noticed that on SPI interfaces the signal name are explicitly defined, as in MOSI (master out slave in) and MISO (master in slave out). Those SPI guys knew what they were doing when defining signal names. 