No that isn't the way it works. The one errored second stays as just that, nothing else is recorded until the line is up again and the hour that that is in will only be partially accurate due to missing data. There is no 'guesstimate' of missing data anywhere in the system.
That is not the way are graphs see it for example ES it increases DS/US keeps increasing when we stop logging into MDWS
Nope, that is not what is happening. You appear to be misreading the way graphs are constructed.
If you have two points to plot, a Google Line Chart just connects a straight line between them so if the gap is umpteen hours and the second point has some error seconds, there will be a slowly rising line between the two which is what I believe you are seeing and the system has been like that since day one.
Try running your cursor along the line of an ES plot with missing data such as William's. You'll only see plot points where there is data, not in between on the hourly divisions as there would be if you were correct. The value plotted are taken straight out of a database table and if no data was uploaded, there is no data to retrieve from that table.
The only place this does not happen is with the SNRM graphs for the shorter time periods where I spent a LOT of time rewriting the Google code to remove the joining up during periods of no uploads so it was clear when there were no uploads (which is why you can often see gaps!) It has been explained before I believe.
It's clearer if the chart is drawn as a Column chart rather than a Line chart as the gaps are then obvious - but Google is a bit weird with the width of the bars and they are often very thin which is why they are currently shown as Line charts.
See attached examples.
BTW this is off my local dev system and this has flags for each user's Country. I am considering putting this live with options to hide them or not show your own etc etc.
We have quite a few overseas users - notably one currently in the Cayman Islands (steubing @ -5 hours) who seems to have an example of a totally unmanaged FTTC line with enormous error counts but no form of divine or man made intervention....