Below fair use Screenshots (obtained from creative commons video license) to depict Active Head Restraint (AHR) deploying in manner in which they were intended,though crash test simulation is of an apparent high speed rear impact. My Intent of these exhibits is so you can see with your own eyes how fast they deploy in their race against the shock-wave effects causing rearward movement of the head and increase of G force.  Timestamp in milliseconds after rear impact can be seen for the record.

Source citing, costa V FCA

Screenshot slow motion video source above https://www.youtube.com/watch?v=iBIfnZ-S4Ls

The AHR's are designed to fully deploy and catch the head before the head starts to move backwards from a rear end collision, they are not designed or intended to catapult the head from close proximity or contact as happened to me.  A signal from the rear vehicle and the AHR releases.  The crash test video starts at -6ms until impact, It can be seen that 25ms after impact the top of AHR has just began to release.

From 25-38ms it is fully deployed closing the driving distance between the head and AHR and can be visualized that the head has not yet made contact with the spring loaded AHR. I believe command deployments such as this do help "lessen" risk of whiplash, that's a good thing when it works as designed and seen here, however im my case my head came in close proximity from rearward movement shutting my door, I do not discount possibility back of  my angled head touched the AHR when it defectively deployed causing my head to catapult at a high rate of speed, but It believe it was the timing of the door slamming shut.  The underside of my chin struck the left side of my chest.

-6ms until impact, it can be observed top of AHR where plastic meets padding, there is no distance indicating a deployment signal has not yet been sent from airbag controller.

At 25ms after impact gap between AHR platic and top of padding can be seen indicating control deployment signal has been received from rear vehicle sensor.  It can be observed the normal driving distance between the head and AHR is maintained.

by 38ms after impact it can be observed command deployment of AHR has occurred closing distance between head and AHR without contact and so fast as to beat the race against the rear momentum force effects upon the heads rearward movement. Total deployment time 14/1000th of a second, with consideration the impact vehicle appears to be traveling at a higher rate of speed than the Insurance institute for highway safety (IIFHS) video.  If you notice there is still space between the head and deployed AHR at 13 milliseconds after impact.

I would agree with FCA/Chrysler that as seen in this video and the IIFHS video, the pre impact distance between the AHR and head there would be virtually Zero chance of injury by a FCA AHR.  as clearly seen from the side profile IIFHSA video the crash test dummy head clearly does not make contact at all until after fully deployed.  But people don't apparently drive that far from AHR's, and they are not informed how far to sit away,  if they even know the AHR's exist at all.   in my case I wasn't driving, my unsuspecting head was in close proximity and catapulted instead of caught.

 video link  at bottom of page presents differing  crash test narrative than I intend to demonstrate here, my intention is to only demonstrate normal AHR and airbag deployments as designed and as I believe my fair use screen shot edits demonstrate.  I believe the full length Tracy Law Firm video linked at bottom of page was for their law-firm to demonstrate a seat failure from a high speed rear impact that is beyond my intention here.  I do not believe the AHR or airbag deployment as seen in below video was focus of investigation nor intended to demonstrate any flaw of the AHR but rather the seats. To be clear my intent is only to demonstrate the normal deployment of the AHR in comparison to Airbag deployment speed and demonstrate the speed of AHR is so fast to beat the shock wave and that as clearly seen seen on insurance institute for highway safety side profile video screenshots after it is fully deployed.

The AHR in Mercedes Benz seen here is cited in legal filings and internet complaints to be the same AHR Grammer AG AHR, it as well with visual inspection as stated in owners manual the no distinguishable markings are available appears to be the same a in the 2017 Jeep Patriot that struck me.  AG manufactured AHRs present  in millions of makes and model vehicles from 2010- August of 2017 when they began washing off oil contaminant with alcohol Grammer/Chrysler joint investigation determined caused  a chemical reaction and random deployments in  Chrysler vehicles reporting non-command (random deployment).  

Attorney cited Below is for video reference only, I have affiliation or retainer at this time.