“Have you proven your case?”

This is a rare occasion that I beg to differ with Bryan Garner. Does anyone detect a usage error in the headline? According to Garner’s Modern American Usage, proven as a past participle is “ill-advised[ ]”:

“Proved”" has long been the preferred past participle of “prove.” But “"proven” often ill-advisedly appears ....

In American English, “proven,” like “stricken,” properly exists only as an adjective ....

“Proven” has survived as a past participle in legal usage in two phrases: first, in the phrase “innocent until proven guilty”; second, in the verdict “Not proven,” a jury answer no longer widely used except in Scots law....

Comments

[Mike]

So what's wrong with Garner's view?

[Ray]

Well, there are these blurbs from the OED Online:

“1957   B. Evans & C. Evans Dict. Contemp. Amer. Usage 399/1   The participle proven is respectable literary English. In the United States it is used more often than the form proved. In Great Britain proved is used more often and proven sounds affected to many people.
“...
“The past participle proven, originally Scots and the usual form in Scottish English, developed from the β forms by analogy with strong verbs like cloven, past participle of cleave v.1, woven, past participle of weave v.1 It is at least as common as proved in current North American English. It is also spreading into other varieties of English, in which the highest proportion of occurrences appears to occur in the past and perfect passive.”

The OED also offers this definition of prove with commentary on the past participle proven:

“1. trans. To establish as true; to make certain; to demonstrate the truth of by evidence or argument.

In this sense the past participle proven (orig. Sc.) is often used. In Sc. Law the verdict ‘Not proven’ is admitted, besides ‘Guilty’ and ‘Not guilty’, in criminal trials.”