IANAL - this is opinion.
Does the other domain owner have enough money to bury you in legal proceedings, ultimately forcing your hand to drop the domain? If so, spend more time to cover your bases.
I rebuilt a commerce site several years for a company that was branded as verbnoun.tld. Another very big brand uses the same verb as their business and domain name, which is also a general term used to describe a type of product.
The very big brand had their very big lawyers contact the business owner, and through a series of very threatening letters for legal procedures and more than $15k in attorney fees, they just quit fighting them and turned over the domains and all branding info.
It was purely a case of who could afford to get buried in legal proceedings... a big company with millions in expendable income, or the small-fry barely showing a profit each month.