Tunnel configuration was correct. The issue was related to the NAT rules. In ASA 9.1 NAT exclusions for interesting tunnel traffic can be defined using a static NAT rule and including the service of http or https. The service is an object that defines the ports being used. In the object both source and destination ports can be defined.
The failure was caused by defining a source port. For example the http service object used a source port as 80 and destination port as 80.
The source cannot be defined as port 80. The workstation will source the packet from a tcp high port. The source port should be left blank and the ASDM will by default add ports 1-65535.