Dual-licensed BSD 3-clause and GPL-2.0 not recognized as such

[adg]

This license file that specifies both BSD 3-clause and GPL-2.0 is only recognized as GPL-2.0. It's a bit mysterious to me why it's not recognizing the BSD part of the file, as it seems to contain a lot of text that fits the matcher.

I wrote a sample program that runs licensecheck against the file, and it gives this output:

$ go run main.go
90.0% of text covered by licenses:
GPL-2.0 at [2276:20460] IsURL=false