See, the problem here is that you already decided that Santa Anna was a despost in ,when any cursory knowledge of Mexican politics and history would tell you that back then Santa Anna wouldn't even exercise the authority he had as the elected president, preferring to spend his time between his Hacienda or in military campaigns. When the Tornell Decree was voted for Congress he was already in San Luis Potosi organizing the Texas campaign. The law was repealed a few days before the battle of San Jacinto.

Also treating filibusters as pirates was the standard back then. Wasn't worse than what happened in San Jacinto.