It's not treason since the Indian government is not an enemy of the United States. Furthermore to be charged with treason there has to be two eye witnesses, "No Person shall be convicted of Treason unless on the testimony of two Witnesses to the same overt act, or on confession in open court."
More likely someone will get charged under the Espionage Act, which has no such requirements... assuming of course that the US Government was not complicit in this.
I honestly think this is a special case, the Indian Government was essentially threatening to ban them from that market. To the fan bois out there that are touting FOSS as the solution... you might want to go read some of the security blogs before you go and do that. You'll quickly realize that it doesn't matter if the OS manufacturers make backdoors or not. ALL OSs have major security holes, Windows has a codebase stretching back nearly 30 years, as does Linux, I can guarantee that both have bugs that can lead to privilege escalation, some of which can be executed with remarkable reliability, e.g. Stuxnet.
My primary concern here is that this violates the Foreign Corrupt Practices Act, as giving the Indian Government the backdoor constitutes a bribe.