Wouldn't that filter act unilaterally on the whole document? The camera shutter speed is so quick that the entire image was captured in a tiny fraction of a second. What was special about just that suspicious piece of writing that it alone behaved differently from the rest by this filter on the camera? Why did the filter not alter the lower loop of the "Y" in "Roy" since it was right next to the date and building name that got turned blue?
-PJ
different inks react differently to different lights and aged inks are drier than fresh inks...
http://www.questioneddocuments.com/vsc/