What happened is I accidently pressed the accelerator and rpm shot to 4800-4900 rpm in neutral. The engine was fully warmed-up. Redline of the engine starts from 5000rpm and revv-limiter kicks in at around 5200 rpm. Does it damage the engine or Am I being overly paranoid.
You are being overly paranoid. While this action isn't good for the engine, it won't harm it. There's a redline for a reason, that being an engine speed you should not exceed. You weren't exceeding this level, so there should be no issue. Engines are designed to take abuse over the long haul. Manufacturers build in a margin of error to help protect the engine from people doing stupid things to them. Your running it up to just below the redline for a few seconds isn't going to cause any issues.