I am in complete agreement that as frum Jews we must be extremely careful at all times as to what impression our actions are making. The point about upstate is unfortunately a very important example.
However, this story makes no sense to be involving a frum Jew. No frum Jew would randomly take a sandwich on an airplane without checking for double wrapping, a hechsher, etc., particularly if it was sitting somewhere and not actually handed out to him. The only explanation I can see (assuming the story is true altogether) is that the sandwich was taken by someone not frum — or even not Jewish — and because it was a flight to Tel Aviv the attendant just blamed it on “those people”. In general many goyim do not differentiate between frum and not frum Jews, and certainly most do not try to hard to be “dan lkaf zchus” on any Jews. . .