the first flag

Kawada, jr.さんご指名ありがとうございます。すごいニュースですね・・・
"flag"は，「旗，信号」などの意味がありますが，『Wisdom英和辞典第三版』（三省堂）をみると，「付箋，題字，目印」などなどがありました。ここでは，「信号」や「目印」を意訳して「最初の兆候」などと訳せるのではないでしょうか。恋人が自分の家の屋根にのっていたら違和感を覚えるのは当然だと思います。（Ume）

Woman stuck in chimney after online dating goes bad
US firefighters rescued a woman from a chimney after she became stuck while allegedly breaking into the home of a man she met online, reports said Monday.

TV footage showed emergency personnel dismantling the chimney brick-by-brick to reach the woman, stuck eight feet down, according to local television channel KTLA.
The man whose home she was trying to get into -- who declined to give his name -- said they had met online and dated a few times.

She seemed totally cool, until the first flag was her actually being on my roof two weeks ago, he told KTLA, adding: I hope she gets help. I hope she stays offline.
http://jen.jiji.com/jc/eng_afp?k=20141023031927a