IMHO, It does not matter whether hindus ate beef or not or eat beef or not. I say this because we forget what 'hindu' is when we try to answer this trivial question.
'Hindu' is a word given by the other people probably persian and other people of the west to the people and civilization living east of the river 'Sindhu'. It is an umbrella term for the people who practices different types of beliefs like animism, monotheism, ancestral worship, nature worship, vedic rituals and worship, shamanism, atheism and various other practices which were handed over to them by their ancestors. This things are not rigidly defined and we keep on changing our values, belief, ideals, rituals to suit our need and the culture we live in. The right word for hindu is 'Sanatan Dharma'.First and foremost, Sanatana Dharma is anadi (without beginning) and also a-paurusheya (without a human founder). It is defined by the quest for cosmic truth, just as the quest for physical truth defines science (this line is copy paste). So we should not care for who did what and why in physical fashion rather see the man's (and yes woman) pursuit for the eternal truth. So in short, yes so called hindus might have eaten beef but it does not mean anything, it just means a hungry man found meat and ate it.