They can cast if they are LOS'd despite being LOS'd after they begin cast. Which is a Major Issue, like super massive issue. Please zeximax, please for the love of all things sheograth respond to this. Unacceptable
Their range is twice or thrice ours too, and can spot stealth players for miles it seems.
the super sight is the only gripe I've ever had with guards (apart from the bug where archers knock you back and down through the grate), and it's rarely an issue anyway