Israel has long been slow and inconsistent at pursuing and punishing attacks on Palestinians and several recent actions are a heartening indicator that they are taking some of this stuff seriously - very seriously - because children and youth's are involved. One is labeling Price Tags terrorism and the other is how they are dealing with this - not just through the justice system, but with a deeper look into their society.
Your labeling Israel's justice system "slow and inconsistent" does not make it so. What's more important, though, is that in your effort to denigrate Israel (yet again), you reveal a fundamental truth: Israel has a system of justice that punishes Israelis when they break the law and subject Arabs to harm.
If someone wishes to conduct a serious study on how efficient or consistent that system is, that's fine. Truth be told, all systems of justice can be subjected to critical analysis of this type (just ask Michael Vick fans, who wonder why their QB spent more time in jail than other NFL players who killed people in DUI incidents).
But a flawed system of justice is a system nonetheless. The Arabs, on the other hand...
The Palestinians? Not so much - I suspect their justice system is as unstable as their politics. But then they are still fighting for their state.
Your caveat represents a common theme. As shorthand, I will, from this point forward, refer to this as the "Older Sibling Argument." This is the argument in which the "Palestinians" are excused, while Israel is criticized, because "Israel should know better."
I find little utility in applying uneven standards. At the end of the day, the "Palestinians" are appealing to the world to support them in their endeavor to obtain a State of their own. In doing so, they should be subjected to the standards by which a state is measured, and this includes the expectation that a system of justice will be implemented.
The notion that they can't seek to do so now is simply incorrect.