Just like the OP's original situation it's hard to tell. Let's say the uniforms in both cases are bogus....they certainly look strange.....but it's not up to TSA to enforce military uniform standards and I personally don't expect them to do that. The second question is just exactly what ID was used to get through security. Personally I have at least four separate acceptable forms of ID. Typically I use my drivers license but I have my passport, GE card, and retired military ID I can use. If I'm traveling outside of the US I have my passport and rather than dig out one of my other acceptable forms of ID I'll use it. There is no law or rule or policy that I can find that says if you're flying in uniform you must present your appropriate military ID. Point is that in either case the potentially bogus "soldier" could have presented a number of other IDs that were perfectly acceptable to get through security.