I assume that each studio is asked to submit a list of three nominees, which the BAFTA members then select from when making their shortlist. It's possible - if a company knows their list will be published - that they might submit names for other reasons than being the best performances. If one or more people are shoe-ins, a third person might be included just for a nice bit of recognition, something to go on their resume.
Obviously I think Dave Jones is amazing and deserves all sorts of awards, but he may just be on the list for recognition, not as a "serious" nomination. After all, it's pretty impressive for a part-time actor who got into all this late in life to be on a list like this at all. But I'm just speculating.
