It's cute, but I imagine--though could be completely wrong--that the meter maids are required to calibrate their time pieces pretty regularly.
Even more likely than that, I imagine that the actual ticket machine from whence came the source of your current annoyance actually serves a dual purpose: printing the ticket and... you guessed it, keeping the time. And that internal clock is likely either synced "live" or is calibrated daily. Again, your point is cute, and even a bit interesting, but your argument boils down to:
Does the meter maid have first-hand knowledge of the time such that he can attest to it in a sworn affidavit; i.e. the ticket. And the answer is: of course. Following that that line of reasoning, the meter maid also does not have first-hand knowledge of... his name (let's assume it's a "he"). He was told his name was "X" by his parents, his mohel, or even by a birth certificate. But that's all second-hand.
All that being said, I don't see why the "ticket machine" is any different than the records that must be kept by state troopers with respect to the calibration of their radar/laser guns. So, essentially, your rebuttal would be raising a question in the prima facie case by attacking the possible neglect or inaccuracies attendant with the calibration of the time piece.
On the one hand, I feel like they'll dismiss the argument out of hand, though, as I write, I fail to see the distinction between a radar/laser gun and a time-piece.