The plot of the "first avenger: confrontation" was largely tied to the video of the murder of Howard and Maria Stark. It was this video that lay down the plan of Baron Zemot to the division of "Avengers", because he knew that, barely, Tony would find out about the involvement of the winter soldier to the death of parents, the split would not be avoided.
The video recorded an important detail: Howard recognized the tanks and called him Sergeant Barnes. And since at that time the winter soldier was not so famous, it caused logical questions about how the father Tony recognized the Messenger Hydra.
In fact, there is a logical explanation, and it is easier than it seems. During World War II, Stark worked closely with captain America, so, of course, at some point he could cross and with his best friend. Also in the "First Avenue", Howard notes that one of his tasks is to equip Steve Rogers and his people, which would inevitably lead to a meeting with tanks.
But this explanation is not the only one. After the death of Barnes, his name was immortalized in the Smithsonian Aviation Museum in Washington, and the face of the tanks on the memorial looks very noticeable, so even if the future winter soldiers and Stark did not have time to cross during the war, Howard still could know him by role in history America.
Though the tanks and there were many years under the rule of "Hydra", having completed a lot of atrocities during this time, as a result he was able to stand up the way. To see what will happen to hero on, fans will be able to serve "Falcon and Winter Soldiers", which should go to Disney + in the second half of this year.