Not necessarily. What if he had a legitimate claim?

It could be evidence that the requests are illegitimate though and being used to harass, etc.. It's the courts call.

I don't get the jail time threat. Not responding to civil process has to be dealt with via civil contempt process. Compelling responses must first be dealt with via monetary sanctions, it's only after the party refuses to respond to multiple, escalating orders on the same discovery / subpoena that a court can jail. This is constitutional.