Did the tank fire a shell by itself in a viral rebel video?

The final version of this video to the tune of the nasheed Qalu innaha Waad has gone viral by the virtue of the spectacular death throes of its tank hit by a rebel anti tank TOW missile in Latakia, Syria. The video obviously features added sound effects in the form of explosion booms which are absent in the long original video. This, in fact, is normal for rebel TOW videos, probably, because the distance is usually too big for ammo explosions to be heard on the rebel side.

However, it's intriguing that the most spectacular part of the video when the tank fires a shell by itself doesn't appear in the original either.

The nasheed version of the video

راائع لواء العاديات عصفورين بصاروخ #تاو واحد الدبابة و حاجز #البركة

Here is the original six minutes long video. The scene with the tank exploding with a shell from the barrel is absent. Now this can make one suspect that the video was not only acoustically enhanced, but was also edited to add a scene that didn't happen. However, it's virtually unheard that Syrian rebels would enhance their videos with 3D effects. The scene itself looks too realistic which would suggest a serious amount of graphics for rebels to do by themselves or purchase from outside.

راااائع ومميز لواء العاديات تدمير دبابة بصاروخ #تاو وإحتراقها بالكامل حاجز البركة 11-8-2014

So I went the YouTube channel of that rebel group and found the scene published lately in a separate video.

شاهد بعد تفجير الدبابة بصاروخ تاو الدبابة تقصف مكان تمركز جنود حاجز البركة بقذيفة 11-8-2014

Now I say that the scene is real but for some reason it was omitted from the original video. The original video, in fact, was edited itself. So it looks to me. It took a while for the tank to die. The rebels apparently skipped some parts when they were editing the first video. So I believe the tank did fire a shell by itself at some point. This really happened.

In fact, this is not the first video of a Syrian tank springing into action by itself after being hit by rebel anti tank weaponry. Here is another rebel video shot in Dariya, Damascus, last year.

داريا - التصوير الكامل لتفجير الدبابة 25-1-2013