Avoid "why." Instead ask about "how" and you'll get lots of "why" for free. "I'm trying to visualize doing this without using sshd and am drawing a blank. It

Avoid "why." Instead ask about "how" and you'll get lots of "why" for free. "I'm trying to visualize doing this without using sshd and am drawing a blank. It's probably something really basic I'm missing; would you mind telling me how you did it?" Key here is to be genuinely interested. If all you want is to slap the other developer around they will know.