I also work at an e-discovery company and can confirm the use of TIFF files as the court-admissible format for producing any sort of document (especially if it has redactions).

Here is an example of the process to apply redactions to a PDF file (or any sort of electronic document). The document is opened in a third-party native viewer with redaction capabilities (and not in the original application like Arcobat or Office). The end-user draws a black box over the appropriate text using the third-party native viewer. This redaction is saved as a separate layer that can be rendered on top of the native document when viewed in the software, as well as printed out. Finally, when documents need to be produced for court, they are printed out to a TIFF-printer driver, effectively converting them to TIFF and "burning in" the redaction layer. The TIFFs are delivered to the courts and opposing council.

I have no personal experience and at best perhaps a vague recollection of having read or heard something, but would document images be or in the past have been used also to make discovery as inefficient as permitted for the opposition? Images require a person to analyze, or pre-processing before electronic search and analysis can be performed against them.

OCR is very good nowadays, so that's not so big a problem - and for big lawsuits (eg patent fights) there are literally hundreds of lawyers hired to comb through the vast array of documents deciding whether they're responsive or not.

The pre-processing is largely automated but there's certainly a portion (maybe 5%?) of documents that need to be hand-classified in the database before they get to the lawyers. It an interesting field - lots of money to be made, intense competition for it, relatively simple technology requirements but a legal industry which has been resistant to technology for quite a long time. Autonomy seems to be the leading software company in this space.

I can't speak for their other products but in my experience their enterprise search product is a useless piece of crap.

When you're billing the client $300 an hour to do a job they can't easily take elsewhere, you don't have a lot of incentive to improve efficiency.

I heard once that NSA guidelines are to print out PDFs, redact portions with a marker and then rescan them into new files.