Why not try 3:22 instead of 3:10? If Pc West could make a mistake, so could Jeremy.
On the call time issue, I'm going by what I've seen rather than things such as PC West's pocketbook (that I haven’t seen).
On their own, the two logged times (3:26 and 3:36) suggest two separate calls. That's not the only possible explanation, of course, but it's an explanation directly suggested by the fact that different call times are logged.
We know that EP investigated this issue and even a year later still hadn't reached a definitive conclusion. It’s not difficult to check two clocks, so why did they fail?
Pc West also logged that the operator said the WHF telephone was off-hook at 3:42. His evidence indicates this occurred after Jeremy’s call ended, which is consistent with Jeremy’s call having started at about 3:36 as there is no proof that Jeremy’s call lasted more than 6 minutes.
Pc West also logged that CA7 was “@ scene” at 3:50. That’s consistent with Jeremy having left home at about 3:42 and driven at a normal speed to the place where he was overtaken by CA7. One of the officers in CA7 estimated that Jeremy was driving at no more than 30mph when overtaken. Nobody in CA7 said Jeremy was going slowly.
I’ll deal with the age discrepancy separately.