It happened again for a different user.
A user can access a partial list of tags, in this case it looks like the user can access annotated tags and not simple tags.
https://gerrit/projects/project1/check.access?account=1000013&ref=refs%2Ftags%2Fv0.3.2[I replaced unicode chars for readability]
{
"message": "user 1000013 lacks permission null for refs/tags/v0.3.2 in project project1",
"status": 403,
"debug_logs": [
"'user1' can perform 'owner' with force=false on project 'project1' for ref 'refs/*' (allowed for group 'user:user1' by rule 'group user/user1 (user1)')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/meta/version' (allowed for group 'global:Anonymous-Users' by rule 'group Anonymous Users')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/meta/config' (allowed for group 'global:Project-Owners' by rule 'group Project Owners')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/tags/*' (allowed for group 'global:Project-Owners' by rule 'group Project Owners')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/heads/*' (allowed for group '3ef1c33f02fd4e4b90b1d03f103c009c57fe68e0' by rule 'group group1')",
"'user1' cannot perform 'read' with force=false on project 'project1' for ref 'refs/*'",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/meta/version' (allowed for group 'global:Anonymous-Users' by rule 'group Anonymous Users')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/meta/config' (allowed for group 'global:Project-Owners' by rule 'group Project Owners')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/tags/*' (allowed for group 'global:Project-Owners' by rule 'group Project Owners')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/heads/*' (allowed for group '3ef1c33f02fd4e4b90b1d03f103c009c57fe68e0' by rule 'group group1')",
"'user1' cannot perform 'read' with force=false on project 'project1' for ref 'refs/*'",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/meta/version' (allowed for group 'global:Anonymous-Users' by rule 'group Anonymous Users')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/meta/config' (allowed for group 'global:Project-Owners' by rule 'group Project Owners')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/tags/*' (allowed for group 'global:Project-Owners' by rule 'group Project Owners')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/heads/*' (allowed for group '3ef1c33f02fd4e4b90b1d03f103c009c57fe68e0' by rule 'group group1')",
"'user1' cannot perform 'read' with force=false on project 'project1' for ref 'refs/*'",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/meta/version' (allowed for group 'global:Anonymous-Users' by rule 'group Anonymous Users')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/meta/config' (allowed for group 'global:Project-Owners' by rule 'group Project Owners')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/tags/*' (allowed for group 'global:Project-Owners' by rule 'group Project Owners')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/heads/*' (allowed for group '3ef1c33f02fd4e4b90b1d03f103c009c57fe68e0' by rule 'group group1')",
"'user1' cannot perform 'read' with force=false on project 'project1' for ref 'refs/*'",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/meta/version' (allowed for group 'global:Anonymous-Users' by rule 'group Anonymous Users')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/meta/config' (allowed for group 'global:Project-Owners' by rule 'group Project Owners')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/tags/*' (allowed for group 'global:Project-Owners' by rule 'group Project Owners')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/heads/*' (allowed for group '3ef1c33f02fd4e4b90b1d03f103c009c57fe68e0' by rule 'group group1')",
"'user1' cannot perform 'read' with force=false on project 'project1' for ref 'refs/*'",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/heads/master' (allowed for group '3ef1c33f02fd4e4b90b1d03f103c009c57fe68e0' by rule 'group group1')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/heads/stable-0.1' (allowed for group '3ef1c33f02fd4e4b90b1d03f103c009c57fe68e0' by rule 'group group1')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/heads/stable-0.2' (allowed for group '3ef1c33f02fd4e4b90b1d03f103c009c57fe68e0' by rule 'group group1')",
"'user1' can perform 'read' with force=false on project 'project1' for ref 'refs/heads/stable-0.3' (allowed for group '3ef1c33f02fd4e4b90b1d03f103c009c57fe68e0' by rule 'group group1')",
"'user1' cannot perform 'read' with force=false on project 'project1' for ref 'refs/notes/review'"
]
}