Not really. I guess it would depend on the circumstances and whether you
came across as chilly or distant. Most likely they would consider the
source and figure you are just trying to be polite or were unfamiliar
with the verb forms involved. Personally, I almost always use the formal
mode, but that's just the way I was taught. It's awful hard to
unintentionally offend that way.

Seanette Blaylock wrote:

David Yehudah had some very interesting
things to say about Mom [OT]:


A lot depends on where she's from. In most parts of Mexico the informal
"tu" is okay unless there is a great disparity in social level or age.
In some parts, particularly around Eastern Mexico, to call someone you
don't know well or who is on a higher social level or older than you, to
say "tu" is a deliberate insult.


Which has me wanting to double-check on a related question: if you're
normally on a "tu" basis with someone and switch to "usted" forms,
will the other person take that as evidence that you're seriously
unhappy with him/her?