Last log line by keyword

You are grepping a cron job's output by hand and want the most recent mention of a task. Each line has the form "<timestamp> <LEVEL> <message>". Given the lines in the order they were written and a keyword, return the ENTIRE last line whose message part (the text after the level token) contains the keyword as a substring, timestamp and level included in what you return. If nothing matches, return the empty string.