Bleeding new caliper.

[MrRaisin]

I put on a new rear caliper and did a brake bleed to get fluid into it. Used the two person method and made sure all air came out and reservoir always at max. What happened though was when the pedal was pumped and then held down, I opened the bleeder to let air out and the pedal went down more to floor sometimes. I closed the nipple and told person to release the pedal. Should this extra movement on the pedal have happened? When finished I checked I could not turn the rotor with brake pedal pressed and also when handbrake on. Car on two rear axle stands as was doing new discs, pads and turned out needed new caliper. Just a bit concerned why pedal went down to floor when bleeding. YouTube vids dont seem to have this! Thanks.