It is possible that IDF hit the wrong target, although it rarely happens. The point is that Syria is a dangerous, terror-supporting country, that wages a constant war on Israel through Hamas and Hezbollah. If Israel wants to survive, it must watch Syria's every move. So yes, Israel violated Syria's aerial space, but it is perfectly justified, and Israel should keep doing this as it finds necessary.
U.S. to defend Syrian rebels with airpower, including from Assad (Reuters)
from the article: IDF lifts censorship of Sept. 6 IAF strike on target inside Syria