וַיְהִי בְלִדְתָּהּ וַיִּתֶּן יָד וַתִּקַּח הַמְיַלֶּדֶת וַתִּקְשֹׁר עַל יָדוֹ שָׁנִי לֵאמֹר זֶה יָצָא רִאשֹׁנָה And it came about when she gave birth, that he (the infant) stretched out his hand. So the midwife took and bound a crimson thread on his hand, saying, "This one came out first." (Bereshis 38:28)
Is stretching a hand outside the mother enough to be considered the first born? Would this count today l'halacha? If not, how is this pasuk understood?