Nate McMillan last coached a playoff series in 2005. McMillan was the coach of the Seattle Supersonics, who came in with a record of 52-30 (a bit of a lucky mark as their point differential was more in line with that of a 48-34 team). The Sonics that year played at the 4th slowest pace in the league and boasted the league's 2nd most efficient offense... but its 4th worst defense.
The Sonics' first round opponent was the 6th seeded Sacramento Kings, who had a regular season record of 50-32 (also a bit of a lucky mark- pythagorean record was 47-35). The Kings had the league's 3rd best offense and 23rd best defense. They were coached by a man named... Rick Adelman.
McMillan's Sonics were not expected to do well by some against the Kings, who featured playoff veterans Mike Bibby, Peja Stojakovic and Bobby Jackson. Meanwhile Ray Allen was the only Sonic who had extensive playoff experience. However, the Sonics-- helped by an out of nowehere explosion by Jerome James-- won the series 4-1, stealing game 4 at Arco Arena and closing it out at home in Seattle.
In the next round, the Sonics faced the mighty San Antonio Spurs, who would go on to win the championship that year. The Sonics were blown out in games 1 and 2 in San Antonio before winning the next two at home. The Sonics were finally ousted by a 98-96 score in Seattle in game 6. They were inches away from taking the eventual champs to 7 games.
Obviously, the parrallels between the upcoming Rockets-Blazers series and the 2005 series between Sacramento and Seattle are limited. Unlike in 2005, Adelman is at the helm of a squad that excels defensively (4th best in the league) and is mediocre offensively (15th best).
I do think it is interesting to point out that McMillan will face the same coach who he faced in the first round the last time he led a team to the playoffs and its a bit surprising this hasn't been pointed out yet.