We hear stories weekly of other companies or individuals that have done damage to homeowners roofs and landscaping. Dead bushes and broken tiles are the sign of an unlicensed roofer, if they aren't a licensed roofer they don't have insurance to be on your roof! Try to get insurance on your car if you don't have a drivers license, don't have your home damaged by an unlicensed individual. By law a Licensed state roofer must post their license number in all advertisements and company stationary, so if you don't see it they aren't licensed.
Ask for their CCC number, ours is CCC 1326693