Here is the IDF version of the events:
Yesterday, following an illegal attempt by Palestinians and foreign activists to erect tents in Samaria’s Hemdat area, in the northern Jordan Valley, security personnel responded to the site with the intent to implement a standing Supreme Court Decision. At the site, Palestinian and foreign activists violently objected, throwing stones and striking Israeli security forces. The security personnel contained the violence with riot dispersal means, seized the tents and detained three Palestinians who were the main instigators, forcefully objecting to the activity. Reports that foreign diplomats abused their diplomatic privileges are currently being reviewed and, if required, complaints will be filed with the relevant authorities.
Israeli Foreign Ministry spokesperson, Paul Hirschson, said a formal complaint might be filed with the French over the involvement of French diplomat, Marion Castaing. “If she did participate then a formal complaint will be filed because that is not the way diplomats behave,” he said.
The IDF notes that a PressTV video shows that the French diplomat Marion Fesneau-Castaing actually punching an IDF soldier (0:52) of this video. (UPDATE: Video is gone; excerpt is here.) A colleague actually tries to hold her back.
I turned it into an animated GIF:
This video of the incident, lightly edited, shows that the IDF only acted when it was provoked. Soldiers politely shooed away the activists until they kept pushing past them. It also shows some activists smiling after getting "manhandled" because they wanted it to be caught on camera.
Castaing is seen on the ground (2:45) apparently lying there voluntarily, or as part of a protest; she certainly doesn't appear to be trying to get up and no one is forcing her on the ground. She is seen smiling at around 3:15 after her supposedly terrifying ordeal. Similarly, an activist who ignored IDF orders to stay away from the truck and who was pushed away is grinning at 2:17.
It is all a play, where the Israel-haters know that the IDF won't do anything serious to them and they are hamming it up for the cameras.
UPDATE: Here's another angle, showing Castaing getting out of the truck at 6:05. It looks like she is hanging onto the IDF and then dropping to the ground; the soldiers seem to be ignoring her as they are looking at the other activists. If the soldiers grabbed her and dragged her out, it was not a very tense scene. Then a minute later, she simply gets up.