I'm sorry if I'm a bit confused, but are you talking about the bump on the back of his foot? If so, then that is a tarsal spur, meaning that he is indeed a male. If not, please specify where exactly the bump is located and how large it is. Thanks.
Its definitely a tarsal spur. All male veiled have them from hatching. And thats one of the luxuries of owning veileds: you always know what gender they are! Dont stress out over it, itd be like worrying about your own belly button. (tarsal spurs and belly buttons would be pretty weird if you dont know what they were)