https://www.washingtonpost.com/news/morning-mix/wp/2014/08/1...
(Of course we can discuss if most of the uses of tear gas are wrong, but lets for a moment think that we have a moment were we need to chase away a crowd of evil persons riotong and threatening to kill perfectly innocent children.)
Given that the result is, among other things, to escalate the situation and increase civil unrest, it's hard for me to see your argument even that far. This is, at best, a smart way to achieve a stupid result.
That's assuming that that's what the government was looking to achieve in the first place. If they were hoping to calm things down and restore order, then it's just stupid through and through.