Golden hearts upon taking damage

After attempting a speedrun, a silverfish hit me which didn't give me damage, but instead gave me a single golden heart. I was so surprised I didn't fight back the silverfish afterwards. This only happened on the first hit. I looked at the history of this bug, but there hasn't been many recent reports. It seemed like the silverfish hit me midair while I was falling, which might have played an effect on this. I wish I had a recording. I wasn't wearing armor, nor had previous damage taken from me (full health).