Regarding the reading of rights. You'd think it would be a slam dunk think that should protect everyone from unlawful arrest?
The fact is.. well it's murky.
http://www.eppersonattorney.com/2015/04/happens-police-officer-doesnt-read-rights/
https://www.flexyourrights.org/faqs/police-didnt-read-me-my-rights/
http://www.nolo.com/legal-encyclopedia/police-questioning-miranda-warnings-29930.html
http://www.pandullolaw.com/Criminal-Defense-Blog/2015/January/Arrested-and-Not-Read-Your-Rights-Myth-versus-Fa.aspx
We don't have all the facts of the case before us to know if this individual had the charges dismissed due to solely not having ''miranda'' rights or if there were other misconduct. I suspect there are some other factors at play, but don't know certainly. Not having Miranda rights read is a common occurrence at least in the city I grew up, especially when it related to drug searches in vehicles.
If he was not read Miranda and then was questioned without then having his rights read or an attorney presented... there would be the problem. But if he was simply taken in without Miranda most cops will get away with this easily. The OP used the term ''motion to dismiss in the interest of justice'' or a ''clayton motion''... I'm sure one of our more familiar posters in law matters would be able to clarify on that... but I suspect it's because the furtherance of having a court case would have been too much effort even under reduced charges and as the individual is from another country unlikely to get far in the court system. Some factors may be the seriousness of the crime, the harm it caused, and that the effort to convict would cause more harm than good. Stuff like that..and lots of questions. Was the pot obtained in a state where it's 'legal' and brought to a state where it's not (an immigrant might not know this so an attorney might argue that), was it a small amount (fairly yes), was the person doing anything else harmful at the time (no).
Still doesn't matter though. An arrest record of some sort will be there.. and besides all that, they will have to admit to possessing/using.
Your overstay was less than 180 days, so I'm pretty sure that won't matter. The arrest however, may be an issue. Just because your case was dismissed, it doesn't mean the stop and search was illegal. On what grounds were you arrested?
