Never send doc. Always pdf. Next time I'm lookin I'm gonna send a jpeg for shits n giggles.
Same goes for references, always, "available on request for the employer who can reach out if they like, no you can't have them. Go find your own clients".
This may be a benefit in this case, as sneaky edits to a JPEG full of text will show up as a difference in patterns of artifacts - original text will be compressed twice, while the edits just once (or once and zero if they save the edited image to PNG). Takes a bit of time and skill to make this unnoticeable.
Same goes for references, always, "available on request for the employer who can reach out if they like, no you can't have them. Go find your own clients".