No, they cut diesel with gasoline all the time. Especially old, stored diesel they are rehabilitating.
Gasoline engines won’t run at all on diesel but a small amount of diesel mixed in the gas doesn’t matter — it’s just extra lubrication like 2-stroke premix, but it would damage cats.
The one thing you really don’t want is ANY gasoline — even just drops — mixed into kerosene for a kerosene stove.
A small amount of gasoline in deisel probably isn’t any different than going from No.1 to No.2, but too much gasoline will create havoc in a diesel.
Per putting diesel into gasoline in small quantities, well, the key is “small quantities”. The same applies to motor oil. It will run, more lubication, more smoke, more carbon, but it will run.