That’s more than 5 minutes late if they were just driving in, probably takes at least another 10 minutes to park, unlock, turn on all the lights, get everything settled, etc.
I wouldn’t use them as a trainer, you’re paying them for the time and they’re not giving you the time.
Defrost in fridge, no other safe way to do it.
I cook from frozen all the time, but I use a sous vide stick in a cooler box (keeps the water insulated so less heat loss), then finish in the air fryer.
EDIT: ITT people who clearly win the lottery every time they buy a ticket
As far as making sure nothing is transmitting, you’re kind of screwed unless you are comfortable dismantling and identifying hardware as technically someone could install a chip that will phone home.
Software side you might see odd traffic coming from your laptop if you run a router that allows you to have such granular information.
Easy, pay someone $$$ to do it lol…
Less jokey, you do need reasonable microsoldering skills unfortunately.
In Australia I paid someone $150 to do mine including the pi chip.