Recover a delete on prem AD user with Azure AD user account?

Experts, I have a client that for some reason deleted his on prem AD user account.  I tried the obvious - ldp.exe, powershell cmdlts, AD administrative center (deleted objects)... and nothing is there.  no user account.  Like there is no record of it existing.  I do have a system state backup but really dont want to go through the whole authoritative restore process.   His account is in Azure AD (but of course being deleted because its syncing with the on prem Azure AD) so hes having to restore it in there every few hours.(Windows servers on prem - 2012 but 2008 R2 domain functional level).

is there just a way to sync that account back down to on prem AD?  or just recreate a new on prem AD user account (for that user)... but I know the user ID will not match or be the same unless I can manually match it from on prem to Azure AD??

Any suggestions would be appreciated.  thank you very much.