Hi deb,
This probably isn't a great deal of help but you could contact Glastonbury Festivals Limited and ask for the Steward Co-ordinator, a guy named Martin Casey. He should be able to give you the name and contact details of the Area Co-ordinator for the stewards in The Park who in turn may be able to point you in the right direction. Martin may also have an Incident Form for you (it's just a steward's record of any significant events, nothing sinister!) which could also help to track Graham down.
I work as a Steward Supervisor in Dance Village so I'll also ask my Area Co-ordinator if he knows the Area Co-ordinator for The Park but I think that's unlikely.
Finally, I'm glad you were ok after Graham's help; it's always good to hear about stewards doing a good job. A warning though. If you do track Graham down, be prepared to meet him at every Glasto from now on - I helped someone in 2008 and she's insisted on getting together for hugs and too much cider together every year since.