sh[it] and What am I missing here?

[Baho Utot]

I have tried this on 11-CURRENT and 10.1 release...........

Just doing some scripting ( thought I was using a bourne shell but may 
scripting was puking) so I came across this........

root at baho-utot:~ # set
_
addsuffix
anyerror
argv    ()
autoexpand
autolist        ambiguous
autorehash
csubstnonl
cwd     /root
dirstack        /root
echo_style      bsd
edit
euid    0
euser   root
filec
gid     0
group   wheel
history 1000
home    /root
killring        30
loginsh
mail    /var/mail/root
owd
path    (/sbin /bin /usr/sbin /usr/bin /usr/games /usr/local/sbin 
/usr/local/bin /root/bin)
prompt  %N@%m:%~ %#
prompt2 %R?
prompt3 CORRECT>%R (y|n|e|a)?
promptchars     %#
savehist        (1000 merge)
shell   /bin/csh
shlvl   1
status  0
tcsh    6.18.01
term    xterm
tty     pts/0
uid     0
user    root
version tcsh 6.18.01 (Astron) 2012-02-14 (x86_64-amd-FreeBSD) options 
wide,nls,dl,al,kan,sm,rh,color,filec

OK tcsh as I thought


OK switch shells

root at baho-utot:~ # /bin/sh
# set
BLOCKSIZE=K
EDITOR=vi
GROUP=wheel
HOME=/root
HOST=baho-utot.bildanet.com
HOSTTYPE=FreeBSD
IFS='
'
LOGNAME=root
MACHTYPE=x86_64
MAIL=/var/mail/root
OPTIND=1
OSTYPE=FreeBSD
PAGER=more
PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/games:/usr/local/sbin:/usr/local/bin:/root/bin
PPID=1373
PS1='# '
PS2='> '
PS4='+ '
PWD=/root
SHELL=/bin/csh
SHLVL=1
TERM=xterm
USER=root
VENDOR=amd
#

Why is the SHELL variable still set to /bin/csh

After the /bin/sh am I into a bourne shell or what?