Update replace files??

Its a silly question, but yestarday i got a email where a guy said:

"I was working in a file "A", before i commit changes i updated the local
folder, and then i lost what i changed on file "A".

this is the question:

Update action overwrite my changes?? Does it replace my changes if I change
a file??

As i said to guy: "i think it isnt possible, svn didnt overwritte files."
Am i right?? or no??

tks.

Igor Max
Received on Mon Apr 2 17:14:24 2007