Until version 1.8.17 a new file created with sudo has the owner/group
root:root, whereas with 1.8.17 it's root:users if users is the primary group of the caller:

Linux system with shadow passwd and without PAM, sudo build from sources, configured with ./configure --prefix=/usr --without-pam


# cat /etc/sudoers
juergen  ALL = NOPASSWD: /bin/touch

with sudo 1.8.17:

$:~> whoami
juergen
$:~> umask
0022
$:~> sudo touch /tmp/sudo.test1
$:~> ls -al /tmp/sudo.*
-rw-r--r-- 1 root users 0 Jun 22 14:39 /tmp/sudo.test1
$:~> 

with sudo 1.8.16:

$:~> sudo touch /tmp/sudo.test2
$:~> ls -al /tmp/sudo.*
-rw-r--r-- 1 root users 0 Jun 22 14:39 /tmp/sudo.test1
-rw-r--r-- 1 root root  0 Jun 22 14:40 /tmp/sudo.test2
$:~> 


Thanks