Normal career path for lecturer in Computer Science
I think that would depend on where and what you teach.  I've been a "computer science" prof for years because at the beginning of my career while working for a "dot com" I was asked to substitute for a class at a very famous design school and the instructor never came back.  Then I went to the department chair with a bunch of suggestions for things I thought they could improve in the program and they made me an assistant professor.  Then they put me in charge of the technical faculty.  Then they let me expand "coding" classes out into things like physical computing and HCI.  And because of this experience (teaching, curricular development, faculty leadership, not to mention panels and publications) I've been hired at other places, and go back and forth between industry and teaching.  

It does sound like you're in the UK but I know a lot (most) schools in the US will hire people with very strong industry experience even if they don't have a Ph. D.  So while having a Ph. D. might be a clearer path to some extent, teaching gigs are competitive no matter what you do.  Working in the industry might not necessarily work against you!