Mechanical Lien Query

[Mauricio A.]

Hello all, 

I have an  investor friend who is retired and I was helping him to obtain a roof contractor to fix a leak in one of his properties.  We contacted one roofer who came out and gave a written estimate for the repair.  The property owner agreed over the phone that the roofer would come out to work on the property the next day.  However, the roofer never came nor returned any of his phone calls on the next day.  A day later, my friend got in touch with the roofer and informed him that he no longer was interested in doing business with him.  The roofer became irate and threatened a mechanical lien against him.  

My question is: would this mechanical lien be legit?  There was no contract signed, only a verbal agreement that the roofer would show up the next day, which he never did. 

Thanks!