Agree ... Very, very unlikely to be your basal..
Basal is designed to work on a slower release system in our bodies. I expect its coincidence it happens around times of basal injections..
These lows will normally be due to too much short acting insulin, and possibly another factor such as not enough carb, exercise during previous 12 hour, etc.
I suspect that everybody mentioning these hypo's coming on rapidly will have had a food bolus within 3 hours prior to the hypo...