I’ve wondered how many people are doing this. At the company I work, there are a couple people I wonder if they aren’t working another job as well. One programmer has gone over a month checking in nothing, and then when pressed on it, checked in about a days work. (I think he’s playing games all week though, not working two jobs)
Another would do some work, then nothing for a couple weeks, do a bit more and then nothing for another couple weeks. I wouldn’t be the least bit surprised if he doesn’t have multiple jobs.