Depriving a person of their freedom, even temporarily is not a "simple misunderstanding". It is understandable for a LEO to talk to a person or even detain a person on a suspicion, but before they arrest and incarcerate a person they should make sure that they know what they are doing. How hard would it have been for these LEO to have checked on the law before they got so deep into this that they felt that they had to charge him with "something" or lose face?
LEOs can talk to anyone they wish. When they insist on a response via the authority vested in them by the state that is not understandable. Your state may be different but what a arrest in MO is defined below.
Arrest.
544.180. An arrest is made by an actual restraint of the person of the defendant, or by his submission to the custody of the officer, under authority of a warrant or otherwise. The officer must inform the defendant by what authority he acts, and must also show the warrant if required.
Not being a lawyer and reading the words, there is no detainment in MO. I always advise folks who carry and who are arrested by a cop (detained
) to not speak a word to the cop(s), comply without speaking, and real slow like molasses in December, and to seek legal counsel immediately afterward or a soon as practical.
Any cop can lie regarding their justification for stopping you.