In House's last scene with Wilson, we get a clear view of House's digital wristwatch. The camera cuts to Wilson briefly, then back to House. But in that few seconds, several minutes have elapsed on the wristwatch.
The quote said to be from Albert Einstein, "Coincidence is god's way of remaining anonymous" is one of many quotes attributed to Einstein that were never said by him. It has also been attributed to Doris Lessing, but there is no source for that either.