There's a few bits of data error that you have in your understanding of the article. For one, you have this:
Now that makes me think that if his average speed between the two points is estimated at 35mph and the areas speed limit is 50mph, with a similar grace that is one giant error in the system.
In actuality he was not personally involved in any of these tickets, these are all separate drivers that work for the company he owns who each got separate tickets for his company on this stretch of road. Here he's using laws of probability to say that he can believe a few of his drivers may have been doing the requisite 12mph above 35mph [47mph is the upper limit of grace] but not all 40 of the accused drivers, which is what prompted his investigation into the photos in the first place. Given this fact, any error in photogrammetry (heh, spell check doesn't like that word, but doesn't know any proper replacements) that you perceived is not as far off as you initially thought. His driver was actually accused of travelling 50mph (22.352m/s) giving that between the two photos it should have shown 8.11m distance between the two instances instead of the 5.67 that the Business owner calculated.
I'm not sure how it is in the rest of the States here but I've lived in two where local municipalities were forced to allow for a 10mph leeway, not for RADAR calibration errors, but for speedometer calibration errors. No two speedo's will read the same. You've got variables such as stretched cables on older vehicles, oversize or undersized tires without recalibration of the transmission, faulty OBD-II computer, hell, even having tires 10lbs over or under inflated can cause speedos to be off by several mph. Also I know for a fact that in Georgia, as laid out by the O.C.G.A., they don't trust the municipality RADARs to be calibrated accurately to within 15 MPH. This is also shown in the fine table as it's not until offenses of greater than 15MPH is there any money allowed to be gathered in fines and costs that would be worthwhile for the municipality to charge that would be able to compensate for the Arresting Officer's time in writing the ticket, let alone the operations of the court. Only Georgia Department of Public Safety Officials (aka State Trooper) are allowed to issue cites for anything 1mph over the limit or higher; County and City Governments have to have a 15MPH margin minimum or else they could face revocation of their RADAR Operations License for 6 months to a year (time when speeding ticket revenue would be nil)*.
Now...on to this point:
The odd thing is the manufacturer of the camera says:
"Optotraffic representatives said the photos are not intended to capture the actual act of speeding, and are taken nearly 50 feet down the road from sensors as a way to prove the vehicle was on the road.
“No one has come to us with a proven error,” company spokesman Mickey Shepherd said Tuesday. “Their speed is not measured by the photos. The speed is measured before the photos are taken.”"
I would have thought that would be enough to get his style of defense thrown out of court.
Here is my contention, and apparently the Judges'(plural) as well (Remember, three different judges have dismissed based on this gentleman's rebuttal.) The photos may not be INTENDED on capturing the act, however, by design they have recorded the speed of the vehicle photographically. In the state of Virginia, this is called VASCAR and is used as a legal method to determine speed from the air without the use of RADAR or LADAR (LAzer Distancing and Ranging). Regardless of intent, the fact remains that there are two images of two points in time with a measurable timestamp that can be used to calculate speed. Granted the mechanics of the timestamp is argued to death elsewhere in this thread but it is simply enough to "cast reasonable doubt" on the accuracy of the entire system. Given all this, the statement "Their speed is not measured by the photos," becomes false. Their speed is most CERTAINLY measured by the photos, even if this is not what the company intended for the device.
That is all that is *supposed* to be needed to be acquitted of charges in our legal system. Complete and undeniable proof of innocence isn't needed. Just something to show that a weak link in one segment of the system can bring down the entire system. There's also this matter of Miranda Rights: "Anything you say can and will be used against you in a court of law" This also goes to the accusers as well. If there's a record or documentation of an event that can shed doubt on the overall case, that's all that [should] be required to break all the other links tied to the accusation
*Disclaimer:: Please note that I am not a Bar Licensed Lawyer, I do not charge fees to defend my friends, I do not advertise myself as a Lawyer and under Georgia law I do not have to be Licensed to be an advocate so long as my friend knows and accepts that I am NOT a Lawyer and a Judge has the ability to recuse me from a case, though none have done so to this date. I also concur that my knowledge of the O.C.G.A. upon traffic law is now standing 2 years old at this point. These values and statements of the O.C.G.A. may have changed in that time but I usually do try to keep current so that I may be aptly prepared to defend myself or a friend in Traffic court. So far I have had an 88% success rate for preventing points from accruing on either mine or my friends' license. Having the fines reduced or removed....not so easy.