I am given to understand that in Martial arts there are no experts. Only people who know a whole heck of a lot more than I do. If someone considers themselves and expert I'll do my best to avoid them.
However if someone far more experienced than me is willing to share knowledge I am more than willing to learn from them.
I disagree with this, I think. An "expert" is merely someone who has achieved a high degree of competence in something. In that sense I am an "expert". Were I not an "expert" I would have little business going around the country teaching seminars etc. It would be rather fraudulent to do this and get paid for it unless I were an "expert".
I think you are confusing the meaning of "expert" with how the term "master" is often used (incorrectly I might add) with a connotation of having entirely "mastered" some course of study. In this sense of the word, I would agree that I tend to shy away from the use of "Master" as some kind of title, although I know some very good people whose organizations use the title master interchangeably with Sensei. Still, it has a sort of grandiose feel to it... as if there weren't more to learn, which is ridiculous.
But expert doesn't have that same feel. It merely means that one is very good at what one is doing. I can't imagine why someone would wish to train with anyone who did not possess some level of expertise. If one possesses a fair amount of expertise, one is, ipso facto, an "expert".