Word usage technically correct, but misleading

As an adjective:

duplicitous

As a noun:

dissimulation

or

equivocation
... the use of the same term in different senses

(Collins)

You might also consider doublespeak, but the connotations of that almost the opposite of your scenario: deliberately hiding unpleasant information behind a pleasant facade.

_{On the road, coming back proper dictionary cites in a bit}

Black's Law Dictionary, fourth edition (1968) has this entry for the term lynch law:

LYNCH LAW. A term descriptive of the action of unofficial persons, organized bands, or mobs, who seize persons charged with or suspected of crimes, or take them out of the custody of the law, and inflict summary punishment upon them, without legal trial, and without the warrant or authority of law. [Citations omitted.]

Likewise The American Heritage Dictionary of the English Language, fourth edition (2000) has this entry for lynch as a verb:

lynch tr. v. lynched, lynching, lynches To execute without due process of law, especially to hang, as by a mob. {Short for LYNCH LAW.}

and this for lynch law:

lynch law n. The punishment of persons suspected of crime without due process of law. {After William Lynch (1742–1820).}

It seems quite clear that merely taking someone out of government custody by irregular means does not satisfy the definition of lynch law given here. Unless summary punishment without legal trial is inflicted upon the person thus taken, there is no lynching. In the present case, it seems far more accurate to characterize the action as "interfering with a lawful police action," "being an accessory to an attempt to resist arrest," or "abetting an escape from legal custody."

The article cited by the OP says this:

Until quite recently, “lynching” was legally defined “as taking, by means of a riot, of any person from the lawful custody of any peace officer,” until the charge was renamed from “lynching” to “Attempting to Unlawfully Remove a Suspect from Police Officers.”

But I am unaware that "lynching" has ever been used in a court of law to describe the taking of a suspect from custody in a situation where no subsequent infliction of summary punishment on the person taken was inflicted or even intended by the taker(s). There is no telling what terminology a particular state will use in its criminal code, but arguing or implying that lynching has ever been widely understood to mean simply "taking, by means of a riot, of any person from the lawful custody of any peace officer" is extremely misleading at best and intentionally dishonest at worse.

Supposing, however, that in some jurisdiction the word lynching does have the narrow meaning that the news report ascribes to it, we still have the problem that most people don't understand the word in that unusual sense. In such a case I would describe the use of the term as "technically accurate but misleadingly tendentious." AHDEL defines tendentious as follows:

tendentious adj. Marked by by a strong implicit point of view; partisan; a tendentious account of the recent elections.

The wording in the OP's example also displays elements of hyperbole, of misrepresentation, and of rabble-rousing.

The most common words I can think of for this practice would be "Deceive" or "Mislead"

Mislead mis·led (-lĕd), mis·lead·ing, mis·leads 1. To lead in the wrong direction. 2. To give a wrong impression or lead toward a wrong conclusion, especially by intentionally deceiving.

Deceive v. de·ceived, de·ceiv·ing, de·ceives v.tr. 1. To cause to believe what is not true; mislead. 2. Archaic To catch by guile; ensnare. v.intr. 1. To practice deceit. 2. To give a false impression.