This is not an inherent truth, even if the law "agrees with you", comforting though that may seem to one's viewpoint, the "law" is by far not absolute in ethical guidance. On the contrary, I can easily spit out counter-examples ... for example, would you have said of German Jews who attempted to defend themselves by fighting back during WWII that "No amount of frustration or desperation gives any [Jew] the right to commit a crime - no matter how they try and justify it by pointing to their circumstances"? This may be an extreme example, but it still demonstrates a particular point that holds (bear with me). I could think of hundreds more examples, including many from apartheid.
A government serves and must be accountable to its people, right? I.e. it must "do its job", agreed? Now, when the government fails to serve, AND the usual formal/civil accountability mechanisms also fail, AND it is by definition against the government's own laws to hold it accountable in any other way, then the people are in effect rendered helpless to hold their own government accountable, right? But think about what that means ... what is a government if it's failing and totally unaccountable? Government isn't an alpha-ape dictatorial authority whose every whim we must just accept as obedient subjects, it's a servant of the people. Clearly accountability is a requirement, but honestly, what mechanisms remain for holding the government accountable when all legal mechanisms are useless? This is one reason the US has the Second Amendment.
I definitely do NOT condone destroying buses, that is worse than useless, it's counterproductive. The buses aren't the cause of the failure. Useless government officials are. Officials who remain safe as ever in their mansions and luxury 4x4s collecting bonuses no matter how many buses are burnt. Shouldn't a problem be dealt with at its root cause.