Seems pretty obvious to me.
The GDC didn't intend for the lexan to be considered part of the bridge for scoring purposes. They're human, they do a good job trying to communicate their intent through the rules but they're not perfect. They'll fix it with a rules update (commonly known in the engineering world as a "change order", happens all the time, get used to it if you really want to be an engineer!).
Anyone who risked building a robot to take advantage of the GDC's oversite without clarifying the GDC's intent first will most likely whine and cry and suffer the consequences.
However, they may get lucky and the GDC will let the current definition stand!
To paraphrase a famous quote, those who live by lawyering the rules sometimes die by lawyering the rules!

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2007 - Rookie All Star - Bayou Regional (1858 - Tyborgs)
2009 - Rookie All Star - Bayou Regional (2992 -Prometheus)
2010 - Champions - Bayou Regional (2992 -Prometheus)
2012 - Finalist - Bayou Regional (2992 - Prometheus)
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