Complete, detailed narrative of Lebanese border incident

This article, from an unexpected source, seems to be by far the most comprehensive one about the incident - and (assuming it is accurate) it answers some questions about the timing in the video:

On Thursday, July 29, 2010, Israel notified UNIFIL that a few Israeli soldiers would be crossing the security fence in order to cut a tree and remove a few shrubs in Israeli territory but near the Blue Line (the actual border between Israel and Lebanon). This foliage blocks the view of Israeli security cameras positioned deep inside Israel. Israel also notified UNIFIL that these soldiers would be escorted by a small patrol which would stay south of the security fence.

The Israeli notification was in accordance with UNSC resolution 1701. UNIFIL then informed the nearby positions of the Lebanese Armed Forces about the planned Israeli activities in order to ensure that there was no misunderstanding. The Lebanese Army notified the local HizbAllah force.

Significantly, the Lebanese Army unit deployed along the border with Israel is the 9th Division, whose commanders and troops are Shi’ites and recruited from the same manpower pool as the HizbAllah.

Around 10:30am on August 3, 2010, about 10 Israeli soldiers with saws crossed the gate in the security fence on foot. This detachment was covered by an Israeli patrol which included a few tanks, armored vehicles, and a command vehicle. As UNIFIL had been informed, the patrol stayed 200-300 meters south of the fence.

When the soldiers approached the tree, they were attacked by small arms automatic fire from both the Lebanese Army’s position just across the border and “civilians” (HizbAllah fighters) in the nearby village of Adissyeh.

Immediately, a few Israeli commanders ran from the command vehicle toward the fence to see what was happening. Snipers hiding in the bush adjacent to the Lebanese Army position fired on them, killing the Israeli battalion commander (a lieutenant-colonel) and critically wounding the company commander (a captain). The sniper fire came from a professional ambush that had been organized on the basis of the advance warning provided by UNIFIL.

Meanwhile, the shooting at the Israeli soldiers north of the fence intensified. Israeli forces opened small-arms and mortar fire on the sources of fire in the Lebanese Army position and in a couple of unfinished houses in Adissyeh. Two Israeli tanks and an armored personnel carrier moved forward toward the fence in order to evacuate the stranded soldiers. At this point a UNIFIL patrol arrived on the scene and the UN officers urged both sides to ceasefire. The firing stopped a few minutes later.

Escorted by the UN patrol, the two Israeli tanks and the armored personnel carrier continued to advance toward the gate in the fence in order to evacuate the soldiers. Suddenly an anti-tank missile was fired from either the Lebanese Army position or the bush immediately near it. The missile barely missed the UNIFIL vehicle and the tanks. The Israeli tanks opened fire on the missile launcher.

Major activity followed. Intense fire — small arms, heavy machineguns, mortars, and RPGs — was opened from both several Lebanese Army positions as well as HizbAllah positions in Adissyeh. Israel rushed additional tanks and artillery to the area and started bombarding all Lebanese positions. One or two Katyusha rockets were launched toward Israel, impacted in open space and caused no damage.

A pair of Israeli combat helicopters arrived on the scene. They attacked the main Lebanese Army position near Adissyeh, and subsequently the Lebanese Army battalion headquarters in the village of Al-Taybeh. The helicopters also attacked and destroyed several Lebanese Army armored vehicles which were parked near the headquarters. Three Lebanese soldiers and a journalist (from the pro-HizbAllah newspaper Al-Akhbar) who was with the troops in Al-Taybeh were killed. Another soldier was killed in the position near Adissyeh. A total of five to six soldiers were wounded. There is no reliable information about HizbAllah casualties.

The fire subsided after little over two and a half hours.

I don't understand why UNIFIL wasn't on the scene initially, since the tree-cutting was known in advance, but perhaps they were observing the Israeli actions from another vantage point.