Mr Thant wrote

If it was somewhere like Shepherd's Bush and you arrived by
Overground, popped into Waitrose (or Morrisson's) and left by
Underground, you'd be more likely to run into it.

IIRC the original event was someone picking a shoe repair near Bow
Church / Bow Road OSI but Euston / Euston Square seems a likely place
too.

It seems to me that if all the touches are recorded, the system
should
be able to recalculate the OOS as two journeys.

As far as I can tell, when you touch back in, it has to decide there
and then whether to reopen the previous journey. Recalculating
retroactively seems to be beyond the capabilities of the current
system.

Does the touch back in have to be at a different barriered zone to
counts as an OSI? If so, returning by exactly the same route can't
trigger the problem.

And what if OOS touch is within the 30 minutes but already over the "2
hours" ?

One, very generous, solution would be to start a new "2 hour" period
each time you touched in

--
Mike D