The current system cannot track 90 days from a passport scan, it has to be done manually via reading the wet stamps and sequencing them. There are some exceptions, such as Portugal's e-gates which are open to UK citizens but only applies to trips wholly involving just 3 airports. When this 90/180 day system was designed, the UK was part of the EU and there were not so many visitors making repeated visits to Schengen. A typical visitor from the USA or Canada would make one or two trips a year and it would be more efficient to look at the stamps. Now some Brits present over 100 stamps in their passport, with varying degrees of clarity, of which perhaps 10 need to be identified and calculated, hence this system rapidly become impractical. Hence EES, which will do this tracking and would almost certainly have prevented this incident so long as it was not that particular traveller's first visit after EES registration. Once EES is in place Brits can resume using the EU's e-gates in both directions and in all locations.