Direct transfer will tag incorrect users with same first part of email

Summary

When using direct transfer for projects: in issues, a user with the same before @ email address will be tagged if the correct user is unverified or otherwise unable to be matched.

Steps to reproduce

1. Create matching user on destination GitLab instance but do not verify abc@foo.com
2. Have a unaffiliated user with same first part of email address. abc@bar.com
3. Do direct transfer
4. Check issues and see tagging of unrelated user

Example Project

(Internal Link)ZD 399296

What is the current bug behavior?

Usernames are tagged that do not match email

What is the expected correct behavior?

No matching and issues are owned by importing user (as documented)

Relevant logs and/or screenshots

Output of checks

This bug happens on GitLab.com