They used to call fouls as fouls were seen, albeit with a liberal allowance for physical play. I saw two triple OT finals games. The first, in 76 I think, Celtics vs. Suns. The teams were mostly down to the deep bench. In the 90s MJ was playing Chuck and the Suns. I think no one of significance fouled out.
Remember when CBS, I think, had a regional game at noon and a national game at three. Growing up in Ottumwa, we would get a lot of Bulls, Kings, Bucks and Detroit as the regional games. Looking back today's kids would be stunned at the level of physicality in the 70s and 80s. The league wanted high scoring games, so no one ever played much team defense, except the Knicks.