Email belonging to former IDF soldier in my Amazon Family group

Hey folks,

Don't mean to sound alarmist with the title but this whole thing is just fucking weird. I was doing some management on my Amazon account today, looked at the group that has only ever included my immediate family for years, and noticed an email I'd never seen before included as the account. The email was a firstname.lastname.yearborn @ gmail situation, so I found the guy on LinkedIn pretty much immediately and discovered he was a former soldier and lives in my neighborhood. Never heard of him. Never seen the email before (his icon in gmail matches his LinkedIn photo for the record). I am the account manager of the Amazon account so I'm the only one able to add anyone and I certainly didn't add this guy.

Anyone have any idea what's going on here? It feels too stupid to hack on an email with your real name, but maybe it was a mistake or something else. Idk. I obviously immediately removed his account and reset our Amazon account passwords. Not sure if it's related but it said my Amazon account was signed into 44 different devices, even though I know of about 4 it might be open on.

Any help is appreciated, thank you!