History is not on his side. There actually was a previous incident when a drone came down in eastern Iran in December 2011. Either it malfunctioned as the US claimed or, according to Iran, was brought down by their aircraft. US did acknowledge then that the drone was monitoring Iran's military and nuclear facilities. 
It brings to mind the experiences anyone of us might have had at a time when we all went outside for recess and the bully, carrying a stick, his weapon of choice, would advance on our game of hopscotch and try to trip us as we jumped over the squares. When we threatened to punch him out, he ran to the teacher (the UN) to complain that so-and-so had hit him when he "wasn't doing nothing."
This drone incident is just one in a string of provocative behavior going back a long way in our history. A few of the more notorious ones occurred after World War II. In December 1952, the Chinese brought down a plane ferrying four CIA employees into Manchuria. The two pilots were killed in the crash but Richard G. Fecteau and John T. Downey survived. They were on a mission to pick up an agent who was part of a covert operation to establish a "Third Force" to turn back the Chinese revolution. Hearing nothing from the Chinese, the US presumed all four were dead.
Two years later, the Chinese announced that they held two of the men, had tried them, convicted them of espionage, and sentenced them -- Fecteau to twenty years and Downey to life. Downey felt immense relief since he had expected that they would be executed.
The US put out the cover story that they were civilian employees of the United States Army and that their plane had strayed into Chinese territory (I didn't do anything wrong; the other guy is making stuff up). Fecteau and Downey had been told in advance of the mission to use a another cover story. The Chinese had used this discrepancy to force the two to reveal their true status and eventually give information about the agency, which they had, in any case, been advised to do by their unit chief.
The Chinese were willing to negotiate the men's release on one condition: the US would publicly announce that they were CIA spies. Fecteau and Downey waited in prison for TWENTY YEARS until Fecteau's sentence was nearly over (he was released in December 1971) and Downey's had been reduced before a US president was willing to admit the truth. President Richard Nixon in the interests of establishing diplomatic relations with the People's Republic after his 1972 visit there stated at a press conference in January of 1973 that Downey was a CIA agent. 
In 1960, Premier Khrushchev announced that a U-2 had been shot down while flying over Soviet territory -- an international violation of another country's sovereignty (the bully gets in your face). Assuming that the pilot was dead and the plane destroyed, President Eisenhower claimed that the plane was a weather research aircraft that had strayed into Soviet territory (I'm innocent -- I didn't do nothing).
Then Khrushchev in a second statement about the event announced that not only did they have the pilot, Gary Francis Powers (Powers was later freed in a spy swap), but they also had found the plane's camera and discovered pictures of Soviet military installations upon developing the film. Eisenhower had been caught in a very public lie.
Two weeks later, at a summit with Prime Minister Harold MacMillan of Great Britain and Premier Charles deGaulle of France that had been in the works for months, Khrushchev asked Eisenhower to apologize (bully is asked to own up to what he did). Eisenhower refused and the summit collapsed when an understandably upset Khrushchev stormed out. 
In August of 1964, President Johnson claimed that the USS Maddox, on an intelligence-gathering mission that, of course, took place in international waters, had been fired upon by North Vietnamese forces. LBJ went on television immediately to tell us about this attack, to say that retaliation was taking place as he spoke, and that he was asking Congress for the authority to "take all necessary measures in support of freedom and in defense of peace in South East Asia." 
It was later shown that our ships had not been fired on on that day and it was acknowledged that the Maddox was not only gathering intelligence but was helping to direct covert activities by South Vietnam and US Forces against the North and that the US vessel had been in Vietnamese waters. (LBJ, a master at bullying, knew how to get what he wanted, but in the end he met his comeuppance when he couldn't bully his way to peace -- and millions paid with their lives). 
On July 2 of this year, people in Iran marked the 24th anniversary of the 1988 downing of an Iranian civilian airliner, killing 290 people, in the Strait of Hormuz by the crew of the US Vincennes, an Aegis guided-missile cruiser with the latest in electronic equipment. The crew claimed to be tracking one of the F-14 jets, which we had sold to Iran before the 1980-1988 war with Iraq, and which is a third of the size of an Airbus S300.
They claimed to have warned off the plane, which was en route from Banda Abbas, Iran, to Dubai, Qatar, and was traveling in a recognized international air corridor. Evidence from the Vincennes showed that when the crew claimed the plane-bus-jet was heading straight for them, the airbus was not descending, but its nose was actually pointing up in order to reach its usual altitude for its flight path to Qatar. 
But bullies don't say they're sorry. In fact, Vice-President George H.W.Bush said just that later in the summer, "I will never apologize for the United States of America. Ever. I don't care what the facts are." 
In 1996, in the face of a suit filed at the International Court of Justice, the US ended up paying millions in compensation to victims' families but made them ex gratia , that is, the payments were made as a favor, and not in recognition of any wrongdoing. By this time US military higher-ups admitted that the Vincennes was within Iran's territorial waters, that the airbus pilots had issued the standard friend or foe code to identify their plane, and that the captain had been overly aggressive (a bully) in his actions. Later on, the entire crew was awarded Combat Action Ribbons that are given for "active participation in ground or air combat during specifically-listed military operations."