You can't make that assertion with any degree of certainty. Based on how his amp is behaving I would hold that to not be the case.imp rise will keep the amp above a 2 ohm load.
I've never seen a 4 ohm speaker that "read" higher than the nominal impedance. Doesn't work that way. Re, what you actually read on a DMM, is always lower than the nominal impedance.Plus I would also guess that the subs dont read exactly 4 ohms, they probably sit higher...I could be wrong though.