In agreement with talrnu’s comment, I think “window shopper” is in fact appropriate here. In usage (which might be better represented on Urban Dictionary and Yahoo Answers), this term is commonly employed to refer to people who walk around both inside and outside of shops, and is used to differentiate such people from those who have more of an inclination to make a purchase.
From Urban Dictionary:
Someone who looks at stuff they can’t buy.
When one visits a store or mall to admire goods rather than to purchase them.
From Yahoo Answers:
It implies [. . .] someone who is not serious (a shopper who has no real intention of buying [. . .])
“Browser” does not sound right to my ear as it seems like an awkward nounification. Most people will think of something they use to view websites. I have not heard the word used this way. It would probably require explanation, which would defeat the purpose of having a single word for it.
That said, I have heard people say that they are “just browsing” to indicate that they are not actively pursuing a purchase at that moment. For your case, I could certainly see someone saying “he’s just browsing.” As far as saying “he’s not a customer”, you have another problem.
Anyone visiting the store is, potentially speaking, a customer. so it’s not ideal to say “he’s not a customer” unless you are pointing to an employee, security guard, pomeranian, etc. You might be clearer if you qualify the word “customer” before you establish this comparison, for example: “he’s not a serious customer, he’s _____________.”
Lastly, another term I know for such a person is to describe them as a looky-loo.
looky-loo
(also lookie-loo)
NOUN
INFORMAL
1.1 A person who seems interested in making a purchase, but whose actual intention is only to browse:
a treat for all the North Shore’s looky-loos: the popular Spring Designer Kitchen Tour
A good business broker will separate the real buyers from the looky-loos, bring in more qualified prospects, and usually can garner a better price for the business.
Source: Definition of looky-loo in Oxford Dictionaries
"Responsible" is a general term, meaning that a person has some obligation, or deserves some blame. All of the other words could be considered "special cases" of responsibility.
"Liable" means you have a legal responsibility. A court can force you to pay or send you to prison. You could do something that is totally dishonest, evil, and unfair, but if there is no law against it, you can get away with it. You have no legal liability. On the other hand, a court may force you to pay some penalty when you've done nothing morally wrong. Like, if you make an honest mistake on your taxes, you can be forced to pay fines and penalties even though you did not intentionally harm or cheat anyone.
"Culpable" means you are guilty of something, i.e. morally responsible. A dictionary that I just checked said "deserving of blame". This can be used in a legal or non-legal sense. "The police believed George was culpable for the crime." "Mary was just as culpable for the end of her friendship with Susan as Susan was."
"Accountable" means that you have a legal or moral obligation. You may or may not be personally responsible. The president of a company is accountable for everything that goes on in that company, even if he personally didn't do it or didn't even know about it. If, say, someone is embezzling money from the company, even if the president has no part in the theft, probably didn't even know it was going on, he's "accountable" because he's supposed to have procedures in place to prevent that from happening.
In the Enron case, we could quibble over the definitions of the words, and I'm sure we could question exactly what happened. But what the fellow is saying is that what happened was not his fault, that he didn't do anything wrong, but that as CEO of the company he accepts that it was his job to keep the company running and to protect the interests of the employees and shareholders, and he acknowledges that he failed in this. That is, he is denying responsibility for doing any of these bad things, but accepting responsibility for having failed to do anything to stop them. (As I say, all I know about Enron is what I heard on the news, I have no idea if Mr Lay was a total crook or if he got railroaded.)
BTW When using "liable" in this sense, we say "liable for". As in, "The court found Mr Jones liable for damages" or "If you cause an accident, you can be liable for the other person's medical expenses." "Liable to" is used with a different meaning of the word, meaning "likely to". As in, "This is very hot. If you touch it you are liable to get burned."
Best Answer
What you are doing is called a voice-over. The terms I've personally seen used to describe the person speaking in a voice-over are:
Edit: