Very likely.

The articles of impeachment were not for the break-ins, they were for obstruction of justice, abuse of power, and contempt of congress.

Whether or not he was involved with the initial break-ins, his interference with the investigation was in an official capacity. He demanded that the Attorney General fire the special prosecutor. Once his the tapes were released it clearly showed him to be involved in the conspiracy cover up from the beginning.

In the end, impeachment is a political act. By the time that the articles of impeachment had come out of the judiciary committee it was clear that he had lost nearly all support in congress.