Well its known about obviously due to the G Clamps installed.
There will be a timescale for its removal dependant on possession availability and seriousness of fault.
The stamp marks in the weld, which I assume is the Cess / 6ft side of the rail will indicate to the examiner the Welder and weld number which can then be used to track back weld portion number, date and other related details.
I do not see an X stamp which would indicate that the fault developed after examination.