LGTM but I'm not sure it's worth to change such things as a bugfix. It totally depends what you write in your expression conditions. And it depends what you interpret as a HTTP target resource.

The 405 (Method Not Allowed) status code indicates that the method
received in the request-line is known by the origin server but not
supported by the target resource.

If you have a condition like in the ticketrequest.headers.get('User-Agent') matches '/firefox/i'
I'd argue that this header is not part of the target resource you requested. Otherwise all resources on te internet would depend on the User-Agent, wich means everybody sees different resources when browing the same page. So getting a 405 is just as valid if you request such a route with the wrong method.