It would be interesting to learn if the word 'intent' feautures anywhere in Thai immigration law? I mean, we all know folk will roll up and claim to have got their departure date wrong and so on, seeking to avoid any formal action.
But in this case, intent clearly wasn't there. The delay and subsequent overstay was not the fault of HHTel's mum.
I also think that you can't really compare normal civil service rules to those officers that have powers of detention, such as certain immmigration and customs officers, where careful application of the laws is required, as wrongful detention is a very serious matter. And this was a borderline detention issue.
I know we live in a different World here, but if this happened in the UK, I think heads would roll.