It's probably because James is not wandering around in his armor that Sam notices Interceptor first and the man second, but when finally notices he makes his way through the crowd.

"James!" he calls out, raising an arm over the crowd to grab his attention.

The half mask he has on does little to actually hide who he is and doesn't really go with his clothes, though it seems Sam has it more for the spirit of things rather then actually being part of the festivities. "Hey-" he starts, his smile dropping away at the downtrodden expression on his friend's face. "Something wrong?"