Okay, for sure the freezer thing is total BS, but some cannabis strains can take light frost under the right circumstances. Here's punto rojo that got a bit frozen:
And then hours later it was totally fine:
To increase freeze tolerance, increase P and K and leach out nitrogen to slow down growth. Slower growth leads to tougher, more lignified tissue. When you increase P and K, this raises the solute concentration in some of the plant tissues without significantly increasing the growth rate, which therefore lowers the temperature needed to actually freeze the tissues.
I'd expect if this frost lasted more than a few hours, it would eventually kill the plant. Some cannabis strains are more resilient than others.