ETag caching fails on hooks endpoint

gistfile1.txt

$ curl --request POST https://api.github.com/repos/ingydotnet/zilla-dist-pm/hooks -d '{"name":"travis","active":true,"events":[ "push" ],"config":{"user":"ingydotnet","token":"********"}}' --header 'Authorization: token ********' --header 'If-None-Match: "45cc5f3c5c128e6a79b9a4d46e8b6c0f"' --user-agent git-hub-0.0.3 --silent --show-error --dump-header -
HTTP/1.1 412 Precondition Failed
Server: GitHub.com
Date: Sat, 26 Jul 2014 17:43:30 GMT
Content-Type: text/html;charset=utf-8
Transfer-Encoding: chunked
Status: 412 Precondition Failed
X-RateLimit-Limit: 5000
X-RateLimit-Remaining: 4980
X-RateLimit-Reset: 1406399175
Cache-Control: private, max-age=60, s-maxage=60
ETag: "45cc5f3c5c128e6a79b9a4d46e8b6c0f"
X-XSS-Protection: 1; mode=block
X-Frame-Options: deny
Content-Security-Policy: default-src 'none'
Access-Control-Allow-Credentials: true
Access-Control-Expose-Headers: ETag, Link, X-GitHub-OTP, X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset, X-OAuth-Scopes, X-Accepted-OAuth-Scopes, X-Poll-Interval
Access-Control-Allow-Origin: *
X-GitHub-Request-Id: AE15A491:2240:58F3CBB:53D3E8C2
Strict-Transport-Security: max-age=31536000; includeSubdomains
X-Content-Type-Options: nosniff

Content-TypeX-RateLimit-LimitX-RateLimit-RemainingX-RateLimit-ResetCache-ControlETagX-XSS-ProtectionX-Frame-OptionsContent-Security-PolicyAccess-Control-Allow-CredentialsAccess-Control-Expose-HeadersAccess-Control-Allow-OriginX-GitHub-Request-IdStrict-Transport-SecurityX-Content-Type-Options