It is normal that CMOS chips survive a much higher voltage if there is
no change on signals. E.g. HCMOS typical only use few uA at 18V, even
they only is made for 6V, as max.

It may be a way to burn inputs too by applying high voltage, and then
switch the input to burn by a high frequence. This will only dammage the
logic that is toggleing. Reset is constant active, and oscilator need to
be stopped. I think that the PIC only use few uA under these conditions,
and that it is possible to burn an input.

It is problems with reciveing PICLIST from denmark, and I have not
recived any emails. Try again if it was problems.

Regards,
Jens Dyekjfr Madsen