Your thinking that an apology might be understood as admitting fault hasn't gone
unnoticed by lawmakers in some countries. I know you're asking about the USA, but I thought to mention (as I commented) that Ontario actually has an "Apology Act" that essentially says that you can apologize for something and that apology is not to be considered a confession, admission of fault/guilt.
Apology Act, 2009
S.O. 2009, CHAPTER 3
Consolidation Period: From April 23, 2009 to the e-Laws currency date.
No Amendments.
Definition
- In this Act,
“apology” means an expression of sympathy or regret, a statement that
a person is sorry or any other words or actions indicating contrition
or commiseration, whether or not the words or actions admit fault or
liability or imply an admission of fault or liability in connection
with the matter to which the words or actions relate. 2009, c. 3, s.
1.
Effect of apology on liability
- (1) An apology made by or on behalf of a person in connection with any matter,
(a) does not, in law, constitute an express or implied admission of
fault or liability by the person in connection with that matter;
(b) does not, despite any wording to the contrary in any contract of
insurance or indemnity and despite any other Act or law, void, impair
or otherwise affect any insurance or indemnity coverage for any person
in connection with that matter; and
(c) shall not be taken into account in any determination of fault or
liability in connection with that matter. 2009, c. 3, s. 2 (1).
There are, of course, some exceptions. You can read the act here.
Edit: This law also applies in British Colombia. See the similar Act here.
According to, MillerThomson Lawfirm, as of Nov. 2009:
To date, seven Canadian provinces have adopted legislation of this sort. British Columbia passed the
first Canadian Apology Act in 2006. Saskatchewan adopted similar legislation in its Evidence
Amendment Act, 2007. Alberta followed with an amendment to its Evidence Act in 2008. Other
provinces that have adopted similar legislation to date are Manitoba, Newfoundland and Nova Scotia.
It is important to be aware however that the Acts only provide immunity from civil liability. They do not
apply to criminal proceedings or Provincial Offences Act matters
And for further reading, The University of Victoria has a draft paper entitled "Legal Consequences of Apologies in Canada"