I used to hit tons of reds on the v3, never an audible clip or even mild distortion. I think they must be off a bit.
It's not off, it's just more accurate than we're otherwise used to.
I have no idea about the 722, but lots of equipment uses analog metering, eg. the sony D7/D8/M1/SBM1. Meaning that these units sense the voltage level of the analog signal and try to correlate that to OdbFS in the digital realm. This type of metering isn't all that accurate or precise, and often varies a bit from unit to unit.
The V3 uses digital metering, meaning it is getting the info for the LEDs, including the over LED, from the digital representation of the signal at every given moment (eg, 44,100 times per second, or 48,000 times per second, or whatever). The over lights light on the V3 by definition when there are 3 or more samples in a row that are 0dbFS.
3 samples at 48k sampling equals one-sixteen thousandth of a second. If your overs are of such short duration, there is no way in the world that you will hear it. So it is not that the V3 has so much headroom or that its meters are off. As folks have said, if you look at the waveform in an audio software package, you will see the clipping. It's just that if you're just barely setting off the clip indicators, your clips are likely to be so very short that you'll never have a chance of hearing it.