It is not disrespect for law but for government that is said to incite the crazies. The shock of this incident is related more to its location than the number of casualties. Disasters caused by man can be much worse. These are already in the hands of organizations far more powerful than Timothy McVeigh and his associates. Indeed, the Oklahoma bombing might not actually have been a terrorist act.
Terrorism is a means to an end.
In Oklahoma City, there were no threats, no demands, and no group seeking credit. The bombing might have been an act of pure madness or revenge. Just a few unpredictable attacks on arbitrarily chosen victims can unbalance and subdue a large population. Twentieth century totalitarians have made skillful use of this method. Remedies Violence can serve as a pretext for the imposition of governmental terrorism, with martial law and the destruction of liberty.