Since there is no permanent paper record in an increasing number of facilities, some might believe digital alterations might be easier to get away with.
Not so, according to S. Sandy Sanbar, MD, PhD, JD, FCLM in a book chapter partly on advantages and disadvantage of electronic records (PDF) from the American Board of Legal Medicine, http://www.ablminc.org/:
Alteration, Destruction, or Loss of Medical Records
... no entry in the medical record should ever be altered or backdated.
In the law of evidence, the loss, destruction, or significant alteration of evidence is termed “spoliation of evidence.” Thus, when medical records that have been altered, or had portions removed, or cases in which the record cannot be found come before the court, the evidentiary concept of spoliation of evidence is invoked. The common law evidentiary inference concept or remedy for spoliation is explained by Wigmore as an indication that the spoiler’s case is weak, and “operates, indefinitely though strongly, against the whole mass of alleged facts constituting his cause” (2 Wigmore
(3d ed. 1940) §278 p. 120 (emphasis added). 
Therefore, alterations to records can prove to be disastrous. Records with alterations are absolutely deadly in court. Document examination is now a sophisticated science. With skill and uncanny accuracy, experts may be able to determine the time that entries were made in medical records and who made them.  [Electronic records can greatly facilitate this process, and there are specialty companies with the forensic expertise to analyze EMR data for tampering - ed.]
Courts reason that destroying or altering records in anticipation of or in response to a discovery request falls under the umbrella of misuse of discovery. Discovery rules provide a broad range of sanctions for the misuse of discovery. Sanctions can include monetary fines, contempt charges, establishing or precluding the facts at issue, striking pleadings, dismissing all or parts of the action, and even granting a default judgment against the offending party. In addition to these evidence and discovery sanctions, many penal codes include criminal penalties for perjury and spoliation.  In several jurisdictions, spoliation of evidence itself is a cause of action in tort. 
Therefore, tampering with medical records may make malpractice cases impossible to defend. Further, providers who falsify a patient’s record may be found civilly and criminally liable. Proof of such charges will result in loss of hospital privileges and even loss of license to practice .
As I look for new avenues to explore regarding the legal EHR, which is an interest of mine (having supervised a Johns Hopkins postdoc's thesis on that topic), gaining expertise in EHR alteration detection is a prime area for me.
Another good source of information on this topic is a new book "Basics of e-Discovery", PA Bar Institute, PBI number 2010-6139. Unfortunately, the book is not free, but is available in law libraries such as the library at my university, Drexel:
EARLE MACK SCHOOL OF LAW AT DREXEL UNIVERSITY LEGAL RESEARCH CENTER
SUBJECT Civil and appellate procedure.
TITLE Basics of e-Discovery.
IMPRINT [Mechanicsburg, Pa.] (5080 Ritter Rd., Mechanicsburg 17055-6903) : Pennsylvania Bar Institute, c2010.
DESCRIPT xii, 160 p. : ill. ; 28 cm.
SERIES PBI ; no. 2010-6139.
CALL NO. KFP537.5 .E4 B38 2010
LOCATION Legal Research Center Pennsylvania Collection
It is my belief that EHR alteration, facilitated (or seemingly so) through the elimination of a permanent paper record, needs to uniformly carry very serious consequences, including permanent loss of involvement in clinical affairs, and incarceration.