No rules were broken. There is no grounds for a DQ. End of thread.
The DQ language has been brought up by you (or others) and is absent from the OP. This is more a question of transparency and disclosure. Rupp won bronze on his own accord, yes, but there was visible assistance in the handing gear to him mid-race. Either the swapping of new gear was sanctioned by an IOC official or USATF (Salazar through USATF officials) snuck it in without much note. Obviously, if any other runners received fresh gear mid-race the point is moot. However, if Galen Rupp was the only athlete in this morning's marathon to receive new gear at refreshment stations, then it is a point of contention for any other runner/country.
Of course, given the nature of man, if this was a non-American runner on this North American site, the flood gates would open. Just observationalism...