I disagree, I was flying at Wellesbourne that day. Saw the wx and heard the some of the R/T.
"The instructor reported that the pilot of G-TGRR repeated the new speed, and shortly afterwards said “I can’t see a thing”.
The instructor asked the student to clarify whether
he meant that he couldn’t see the lead helicopter or
that he had lost all visual reference, but there was no
reply. The instructor made numerous further attempts
to contact G-TGRR on 123.45 MHz. . ."
"The witnesses stated that the aircraft was clear of cloud
and in steady level flight prior to the initial pitch up.
Nevertheless, in the degraded visual environment the student pilot may have had limited visual references,
especially whilst in a nose up attitude, and may have
become disorientated."
Carb ice. . ? Well they would say that wouldnt they. . .
IMHO