From your log the error is:
=====
Removing iamerican ...
Can't find string terminator "`" anywhere before EOF at /usr/share/perl5/Debian/DictionariesCommon.pm line 457.
Compilation failed in require at /usr/sbin/remove-default-ispell line 3.
BEGIN failed--compilation aborted at /usr/sbin/remove-default-ispell line 3.
dpkg: error processing iamerican (--remove):
=====
Thanks for your report.
From your log the error is: perl5/Debian/ DictionariesCom mon.pm line 457. remove- default- ispell line 3. remove- default- ispell line 3.
=====
Removing iamerican ...
Can't find string terminator "`" anywhere before EOF at /usr/share/
Compilation failed in require at /usr/sbin/
BEGIN failed--compilation aborted at /usr/sbin/
dpkg: error processing iamerican (--remove):
=====
It's different from bug 223807 .