A ready asked me recently if a resume is a legal document.
Yes and no.
The resume IS a legal document if the candidate states on the application:
"Please See Attached Resume" and then signs the application... that makes the attached resume part of the legal application.
But otherwise, technically speaking, the resume is a marketing document, not a legal document.
However, intent to defraud can tie into the resume if your client lies on the resume. So make sure that your client does not make up credentials, degrees, etc. (That's a good idea anyway!)
However, omitting short-duration jobs or otherwise using your writing abilities to minimize a client's "problem areas" is generally acceptable.