Yes, snipe software can be set to any time you want. One major provider used to recommend setting it for six seconds, but people got wind of it and it's more common to use 5 seconds these days.
The issue with the "possible" shill bidder is that sellers often drop in a "minimum I want it to sell for," or "let's put this in to see if can nudge things up at the end" bid, and use a brand new, nil feedback ID.
Anyway, cross fingers and good luck to the seller and buyer - let's hope it's worked out well for both.