Have you ever closely examined the output from this class of bulbs? I know when I did I found evidence of noticeable blue, green and other wavelengths leaking through or around those bulb's red paint and/or glass tinting.
Try looking at the bulb's reflection on the business side of a CD disc. That's also how I discovered the blue light coming from the red LEDs. I now make this simple check for all of the electronics in my darkroom that sport "red" indicator lights.
The worst offenders get opened up and have small squares of Rubylith applied. A few minutes spent and they then become completely safe for life.
It's also possible that the safelight bulbs to which you refer have been improved since my last look. And admittedly most people will not need 60 minutes of safe exposure. Often 5 minutes or so is sufficient for them.
But its nice to know there is no voodoo involved, and the situation can be easily discovered and mitigated.