If Gero caught Piccolo off guard the same way he did and Vegeta was the only one who could hear the Namekian, do you think Piccolo would call for Vegeta's help?
Dunno, green man was still pretty proud back then, he even said as Kamiccolo (which took away some of his pride imo) that there's no way he'd use something a Saiyan did use.
Vegeta said he didn't care if Piccolo got bodied by Gero, but immediately questioned if he'd be unnecessarily giving Gero more energy in the process. With the way it's stated, Vegeta didn't seem to be up for Gero getting stronger.