I've always felt that the "not a match" was misleading but that does not mean that Bootman's Boots are in any way related to the crime.
It could simply reflect the general reticence of various officials to give out any information.

If there is the slightest difference between the crime scene print and the test-print of the boot made at the crime lab, then those two prints are not a match. However, that does not mean that the boot did not cause the crime scene print.

I just think that if the lab said the boot was likely to have caused the print, the authorities would have had to have done something more in the interim simply because of the threat if the story leaked out.