The 46-year-old Australian paid credit to Paul Anderson's side, who captured the league leader's shield for the first time this season, but said that lessons must be learnt before next week's finale.
"It was a tough old game, that's what we expect at this time of year," Sky Sports News quotes Smith as saying. "We were a bit off in some areas.
"I didn't think we were composed, we didn't quite control the game like have in recent weeks but part of that was down to Huddersfield. They are a dangerous team and they threw a bit at us.
"I thought the effort was there but our kicking game was poor in the first half. I thought we were a bit edgy as if we were trying too hard to get the game put to bed too early. We managed to get through and we'll take our lessons from it into next week."
Wigan Warriors and Leeds Rhinos face off in the second semi-final this evening.