That is a problem. It means the sample rootfs was likely not unpacked by root (only root can preserve sudo permissions). There are many other files which would also have failed, you just found the first thing most people run into when sample rootfs is unpacked incorrectly (similar issues with not using sudo during apply_binaries.sh). On JetPack you should use your regular user, and then it prompts for password…but with command line you just have to use sudo directly for rootfs and apply_binaries.sh.
If you fix just one permission there will probably be hundreds of other issues you’ll find over time…flashing again is probably required. Delete the rootfs directory content, unpack again with sudo, and apply_binaries.sh with sudo. Flash should then work. The other parts of the installation software do not require sudo.
Extra note: Make sure you are not using a non-Linux file system type, e.g., if you use a thumb drive you have to reformat before using it…VFAT and NTFS won’t work, ext4 does. Check with “df -H -T”.