Maybe. I know a certain professor who lives in Milwaukee (an urban geography professor) who I would trust to know his field. The problem is that I can't exactly call on him as a source and expect people on a forum to take my word for it, as I could very well have even gotten his logic wrong. Not to mention that no one else on this forum knows this guy, but I could point to something he's published.
And being first person to something holds a higher level of value than second-hand evidence, but the conflict I often encounter is really how much of the debate that person really participated in. Someone could have been in the military for 10 years, but that doesn't mean that they fully understand what escalated the conflict they were in. If they were a witness to an event, they can talk about their experiences and what they've done, but if they debate on a subject that they didn't participate in directly, they can't use themselves as a first-person source in that regard.
That's where first-person sources get difficult to debate.