In a meeting today*:
Josh: I couldn’t read Greg’s handwriting even if you put a gun to my head.
Joe: Has this been tested?
Caity: Joe probably has all the things we need to facilitate such a test.
Josh: Go ahead and pull the trigger now. I’m never going to figure it out.
* While the words were actually spoken certain implications are not true and are best left to the imagination.
I don’t know; certain situations can tend to focus one’s mind (that which is deemed “impossible” in one state of mind is sometimes readily achievable in another). The subject’s comment notwithstanding, I say it would need to be tested before a conclusion could be made. The challenge would be in setting up the test such that the subject truly believed in his imminent peril (and not getting arrested for it).
Those on the left (and criminal gangsters, but I repeat myself) would have a great deal of experience in this sort of thing also. You’d only be taking a general sort of test (established doctrine, actually) and narrowing its focus to that specific problem of deciphering poor handwriting.