However, it's not that the UN did not say anything. It's hard to find, but there is an article about the event. And also a statement by Ban ki-Moon.
The article leaves nothing to imagination as it uses the word "triggered":
During the meeting, both parties renewed their commitment to the cessation of hostilities and to resolution 1701, which ended the conflict between Israel and the Lebanese group Hizbollah and calls for respecting the Blue Line, as well as to work with UNIFIL to ensure that incidents of violence are avoided in the future.One might wonder how close to the truth that is. I mean... Israel did it with knowledge of UNIFIL and the next day, on August 4th, 2010 it was not a problem for Israel to do their routine work very close to the Blue Line:
The incident was triggered by Israel’s announcement of its intention to cut down a tree in the proximity of the Blue Line. UNIFIL said in a statement issued earlier today that the tree is located south of the line on the Israeli side.
“The exchange of fire started although we did our best to prevent it,” Alain Le Roy, the top UN peacekeeping official, told reporters in New York, stressing that UNIFIL helped to mitigate the violence, which lasted some 30 minutes, negotiating a ceasefire to end the fighting.
The UN website has also a section "News Focus" on the Middle East. Surprisingly these are the mentioned latest developments:
Secretary-General condemns deadly rocket attack in southern JordanNo mention of the border clash which left 4 people dead. No mention of the other rockets at Eilat which fell on the 2nd of August.....
UN official calls for return of Palestinian families one year after eviction
UN urges restraint after rocket from Gaza hits Israeli city
Kites fly high over Gaza as children at UN summer camp soar to new world record
UN envoy deplores takeover of Palestinian homes by Israeli settlers
Mr. Le Roy, who serves as Under-Secretary-General for Peacekeeping Operations, called the existence of the tripartite mechanism bringing together UNIFIL, Israel and Lebanon an “important achievement.”If this is as good as it sounds (if it comes from the UN I have my doubts) I feel pity for torn Lebanon by sectarian military and ideologically conflicts.
He said that he is very glad that the two sides accepted the UN’s proposal for an urgent tripartite meeting.