What's Really Happening In Syria?

The first victim of war is the truth and when the bombs and bullets start flying it is hard to know who did what to whom and when but the tension between Syria and Turkey doesn't look like it's going to end well after six days of firing mortars at each other after a Syrian shell landed on the Turkish side of the border and killed an adult and four children.
Turkey responded with shells of their own and they have been firing them at each other ever since.
So why did Syria fire a mortar into Turkey, a NATO member, in the first place? If it was by accident, apparently their target town is situated right on the border and a slight over calculation would see a shell landing in Turkey, then to do it once is bad enough, but to do it six days in a row? When NATO is itching to get involved? Are the Syrian military that stupid?
Apparently so because it's continuing but there are a few media outlets not quite so sure that the events are how they have been explained.
RT is claiming that the mortar that landed in the Turkish town is a design specific to NATO and was given to Syrian rebels by the Turks and the same ones which the rebels have been firing at downtown Aleppo for the past week.
Of course RT is the Russian state mouthpiece and the Russia Government is siding with Assad and the Syria military but the German state TV channel, ZDF, reporting on the attack,
initially reported that it was the Syrian rebels who fired on the Turkish village, even claiming that the Syrian rebels officially claimed responsibility for the attack and quoting a local Turk saying 'The Syrian rebels try to draw us into their  conflict. We have to be very careful here.' Turkey today called for 'international action' on Syria.
Who to believe? I certainly don't trust the Syrians military or Assad but nor do i trust the rebels who today killed dozens of people in two suicide bombings in Damascus. Anything from NATO should be filtered through a filter of an organisation that has been looking for a legitimate way into the conflict for months and the UK and US lost all right to be considered a fair and balanced broker a long time ago.
Who to believe then? The rebels would be the largest beneficiary of Turkey entering the conflict and Syria have nothing to gain and everything to lose by aggravating Turkey but who knows the truth and as they argue it out, civilians die and once you are dead it doesn't really matter whether it was a Turkish, rebel or Syrian army shell that took you out. The second victim of war is always the innocent civilian cowering in the middle just trying to stay alive.