Yea right, "back channels" I wonder what is wrong with "front channels".
In reality nothing that was not seen before from both sides of the fence, did take place. Exactly nothing.
If one think that barrel roll over NATO plane is too rude, what would he/she think about NATO jet shooting virtually unarmed Russian bomber from behind? Perfectly normal... ? Come on.
And at what distance can a potentially hostile aircraft, from any country, be accurately determined to be 'virtually unarmed' as you say, hmm?
It is normal for countries to send an aircraft to investigate military aircraft and naval vessels of other nations, operating in international airspace or waters, near their home waters and airspace. A few countries, for whatever, have had their aircraft observed performing some rather reckless maneuvers while they are checking out the aircraft or naval vessels they were sent to investigate.
Having a set of ROE, and having those known to nations which have pilots who sometimes endanger other aircraft or naval vessels just seems sensible to me. In the case of the US, a mid-air collision involving a P-8 Poseidon could result in the loss of a USD$200+ mil. aircraft and the aircrew. For those who think that could not happen, there was a mid-air collision involving a PLAAF fighter, and a USN EP-3 in international airspace off the Chinese coast, this was back in mid-2001 IIRC.
Similar sort of situation applies to naval vessels. Even an accidental collision (as opposed to deliberate action or attack) between an aircraft an a naval vessel could effectively cause a 'mission kill'. This would be especially true if there was heavy damage to sensors and/or comm arrays. A CVN which loses radio and radar cannot function as a carrier until the kit is either repaired, or more likely replaced. The same holds true for air defence ships kitted out with SPY radar panels. If one (or more) of those panels are damaged, then there is a gaping blindspot in the radar coverage the vessel has or can provide. That is assuming that all the arrays are not knocked out.
Especially after the incident with the USS Vincenes in the 80's, there is a hesitation to shoot, but if an aircraft (or vessel, like one of the Iranian FAC's) presents a threat to a US aircraft, vessel or crew, at some point the ROE will come into effect and there will be a response.