That is not true.
State v. Furutani,
873 P.2d 51 (Haw. 1994).
Circuit court's grant of new trial in case
involving theft and failure to report income was affirmed
because jurors
discussed the defendant's failure to testify, making remarks that indicated
they
believed if he was innocent he would have testified on his own behalf and
try to "prove his
innocence."
...
United States v. Hall,
85
F.3d 367(8th Cir. 1996).
Remand required for government to rebut
presumption of prejudice where jurors overheard
bench conference where other
crimes discussed.
...
State v. Larue,
722 P.2d 1039 (Haw.
1986).
Second degree rape and first degree sexual abuse convictions were
reversed and remanded for a
new trial because juror relayed her own experiences
when she was once touched as a child,
thereby vouching for the minor child's
testimony.
...
Gibbs v. State,
291 S.W.2d 320 (Tex. Crim.
App. 1956).
Criminal conviction and sentence were reversed because,
during punishment deliberations, juror
remarked to those jurors wanting to ask
for suspended sentence that other jurors wanted
defendant to get forty years,
after which the jurors who were originally in favor of a suspended
sentence
voted to give defendant some time in the penitentiary.
...
Russ v.
State,
95 So.2d 594, 600 (Fla. 1957).
"Where a juror on
deliberation [relies on or] relates to the other jurors material facts claimed
to
be within his personal knowledge, but which are not adduced in evidence . . .
it is misconduct
which may vitiate the verdict."
There are a
number of such cases mentioned in the link. The above are just a few I noticed
while skimming through the document.
