Sorry if the snark (or the crudeness) was too much.
Anyways, I believe that you've seen many incidents over many years that show to you that anything is possible. I also know that, presuming you don't have an eidetic memory, you are inherently biased towards those results which stray from the norm. What's more, you don't really seem to realize it.
The definition of reasonable is pretty subjective, but I'd say that anyone who claims that serious concerns about UConn stringing together two halves like the first half of the BYU game either A) is underestimating how well we can predict the outcome of basketball games or B (and more likely) has absolutely no conception of how large the gap between Texas A&M and UConn really is or C) is going to be worried about any level of uncertainty whatsoever.
Just to throw some numbers out there, we're a 37% 3pt shooting team that shot 0-8 in the first half (with a normal level shot difficulty). They're a 33% 3pt shooting team that shot 5-10 in the first half. The odds of that happening are about 1/125. The odds that they'd do the equivalent over two consecutive halves are therefore 1/16,000. Sure, crazy things happen, but I wouldn't hold my breath on UConn missing all of 8 or more shots and their opponent shooting 50% or better from three in a half again in this tournament.
One more example of why serious concerns about a repeat of the BYU performance that causes us to lose to Texas A&M are unreasonable: If you take Massey at it's word (it's crude and imperfect, but it's observations have lined up well with the outcomes so far and it's probability seems reasonable), Notre Dame is 14 times more likely to beat us that Texas A&M.
Let that sink in for a second.
I'm not referring to the odds that Notre Dame will beat us if we play them. I mean, the odds that both UConn and Notre Dame beat their remaining opponents AND that Notre Dame beats us in the finals are 14 times greater than the odds that Texas A&M will beat us tonight. In case you're wondering, the odds that Stanford beats us are four times higher than the odds that Texas A&M does. And, by the way, the Massey odds that Notre Dame beats us if we play are only 21%.
So, to quote The West Wing, a fan worrying about Texas A&M is like Butch and Sundance peering over the edge of a cliff to the boulder-filled rapids 300 feet below, thinking you better not jump 'cause there's a chance you might drown. It's the fall that's gonna kill you.