Perhaps it's a bit like one of my runs years ago. I pulled an 8.3 @ 325 mph in the 1/8 but slowed to a 13.2 @ 108 in the 1/4. The acceleration and braking was brutal.

The clocks simply blew the 1/8 mph somehow.
Last weekend, a local track was giving everybody a 2.4 60' time in the right lane but the left lane was registering properly.