m25 J3 speed limit change in average cam section

[rodney59]

Heading soundbound on M25, the roadworks at J2, reduce the limit to 50mph and there are average speed cameras. However once pass what I thought was the final average speed camera (and the roadworks have ended) and could see the NSL signs up ahead - I floored it. This is just by J3 (M20) turn off. Only to see about about a mile further on another set of average speed cameras!!

Now this section has the change of speed limit in it (from 50 to 70). Question is can they use them, given that the limit changes?

What I'm really worried about is that I probably averaged 85-90mph in that section - guess I will have to wait and see if anything comes through the post.