What explanation did Barrymore give for his clandestine visit to window at night ?

In Chapter Nine, Watson and Sir Henry followed Barrymore to the room. Sir Henry confronted the butler, who initially claimed he was only fastening the window. When pressed, the butler then admitted he was holding a candle to the window for someone's benefit, but refused to reveal any more. Watson then noticed another candle light across the moor. When Sir Henry threatened to fire the man, Mrs. Barrymore appeared and admitted the truth: the convict Selden is her brother, and they were leaving food nightly for him.