L.R.
It sounds first like you need to take a deep breath and a day to calm down. You and the teacher are getting off to a very poor start on both sides here.
You are already calling her a liar and the "school" year has only just begun. She may not be a great communicator; she may indeed have meant time out and used another term; she may even have mistaken talking to another parent for talking to you. (She barely knows the parents yet, right?) Give her the benefit of the doubt and drop the anger that she has "lied" to you. Maybe she even did lie to you just to cover her backside, but you cannot prove it, and you do not say here that she never spoke to you -- only that she spoke to you, she did not use the term "time out" and your child did use it.
Find out the preschool's policy and her classroom policy. Does the teacher and/or school use time out? What does "time out" mean? Your child may call it "time out" to be told he has to leave the line and sit down for a moment, whereas the preschool may say, no, it's not a time out, we just ask the children to step aside for a moment, time outs are longer and reserved for very specific behaviors. Find out! Do not go on what a young child says, even if your child is very honest and accurate -- young kids tend to see things in a very self-focused way so a slight correction may be seen as a huge, awful discipline by them. Do not go on what "someone" said you about "long time outs" -- find out for yourself.
If the school IS using actual time outs frequently, I would talk to the teacher and director together and calmly, without accusations, ask them why they choose this particular form of discipline. Is it something they have found effective? Is this an especially strict preschool or does it focus more on play and socialization? If they say yes, we use time outs for what you consider small things-- then probably this preschool is not a good fit, and you need to find one where redirection, distraction and teaching better choices are used.
If a school or parent uses too many time outs for every little thing, time outs lose any impact,and the child won't learn anything. If you truly feel this teacher uses them too much (if she is really using what I'd call a time out) then she may be inexperienced with handling kids this age.
But before you leap to the conclusion that what your son says is happening is exactly the way it's happening -- talk with the adults involved. Don't make it a quick conversation grabbed as the teacher is getting kids out the door at the end of the day -- schedule a specific parent-teacher conference and ask to have the preschool director present too. Don't go in defensive or upset; go in asking to understand what your son's saying at home and askiing to learn about their philosophy on discipline. If this is not a good fit, find another preschool. Preschool is optional, not required, and you can take your child and your business elsewhere, but base it on a calm discussion and maybe some classroom observation time too.