No, That was just NESOs story.
Thee whistleblower said that in fact it was far worse. Do learn to read.
As it happens gridwatch records frequencu and on June 23rd ther were periods where frequency was outside NESOs standards ob 49.8Hz-50.2Hz
mysql> select timestamp, frequency from day where timestamp like '2026-06-23%' order by frequency asc;
+---------------------+-----------+ | timestamp | frequency | +---------------------+-----------+ | 2026-06-23 18:00:31 | 49.695999 | | 2026-06-23 18:55:32 | 49.716 | | 2026-06-23 18:15:32 | 49.720001 | | 2026-06-23 19:00:32 | 49.73 | | 2026-06-23 18:25:32 | 49.737999 | | 2026-06-23 18:10:32 | 49.761002 | | 2026-06-23 18:20:32 | 49.77 | | 2026-06-23 17:55:31 | 49.777 | | 2026-06-23 18:30:32 | 49.784 | | 2026-06-23 18:50:31 | 49.786999 |Now they are allowed under exceptional circumstances to go as low as
49.5Hz and up to 50.5Hz but that is a definite issue to be reportedThe story is that they exceeded their own limits but claimed 'nothing happened' and the whistle blower *claims* that orders were given to erase records of internal decisions made with respect to this deviation.
If we look at the period in sequence and do not omit any readings - that is from 17:55 to 19:00: mysql> select timestamp, frequency from day where timestamp < '2026-06-23 19:10:00' and timestamp > '2026-06-23 17:10:00';
+---------------------+-----------+ | timestamp | frequency | +---------------------+-----------+ | 2026-06-23 17:10:31 | 49.876999 | | 2026-06-23 17:15:31 | 49.827 | | 2026-06-23 17:20:32 | 49.891998 | | 2026-06-23 17:25:32 | 49.859001 | | 2026-06-23 17:30:32 | 49.821999 | | 2026-06-23 17:35:32 | 49.839001 | | 2026-06-23 17:40:32 | 49.846001 | | 2026-06-23 17:45:31 | 49.812 | | 2026-06-23 17:50:32 | 49.825001 | | 2026-06-23 17:55:31 | 49.777 | | 2026-06-23 18:00:31 | 49.695999 | | 2026-06-23 18:05:32 | 49.816002 | | 2026-06-23 18:10:32 | 49.761002 | | 2026-06-23 18:15:32 | 49.720001 | | 2026-06-23 18:20:32 | 49.77 | | 2026-06-23 18:25:32 | 49.737999 | | 2026-06-23 18:30:32 | 49.784 | | 2026-06-23 18:35:31 | 49.902 | | 2026-06-23 18:40:32 | 49.915001 | | 2026-06-23 18:45:32 | 49.867001 | | 2026-06-23 18:50:31 | 49.786999 | | 2026-06-23 18:55:32 | 49.716 | | 2026-06-23 19:00:32 | 49.73 | | 2026-06-23 19:05:31 | 49.804001 | +---------------------+-----------+WE can see that it was remarkably unstable. Symptomatic not of the 'nothing to see here' claim of NESO management and looking far more like 'disaster averted by the skin of our teeth, Ssh" don't tell'