The biggest cause for concern was that one of the two issues was also a problem in the 49ers' preseason opener at Kansas City a week earlier.
"I don't think any of us should be pleased right now," quarterback Brian Hoyer said after a game in which the 49ers committed five turnovers and set themselves back with 11 penalties for 86 yards.
"The biggest thing (is), how do we respond? Do we take it and look internally and make the corrections? Or do we say, 'Ah, you know it's a preseason game, we'll move on.'
"I think we have the guys that have the right attitude and we'll see how we respond."
The response to 17 penalties for 131 yards in the opener against the Chiefs wasn't exactly what new coach Kyle Shanahan had hoped. But the 49ers were able to overcome them with 434 yards of offense without a turnover at Kansas City in a 27-17 win.
The offensive output was down (243 yards) and turnovers way up against the Broncos, with the predictable result, Shanahan admitted.
"Anytime you have four turnovers in a half, (losing is) not surprising at all," he said. "Actually, I would have predicted if we had five turnovers in a game and got zero, I would have predicted the score to be a lot worse."
The turnovers ranged from fluky (Hoyer had the ball slip out of his hand while beginning a passing motion) to unfortunate (a short punt hit Jaquiski Tartt, who was blocking in front of the return man) to good defense (Broncos cornerback Chris Lewis-Harris snatched an interception away from Marquise Goodwin as he attempted to secure a poorly thrown pass).
Shanahan labeled the game as a whole "concerning," but also found reason for optimism in its wake.
"I thought the defense did a pretty good job considering that we had 27 points off turnovers," he said. "We put them in some very tough situations. Considering the situation we put them in, I'm not upset with the defense right now."
Hoyer noted he's glad the turnover- and penalty-fest occurred in a game that was played in the preseason.
"This is our first time handling a little adversity as a team as the 2017 49ers," he said. "Now, you just got to see how you respond to it. Are we going to take it and learn from it, and come together and come closer? Are we going to, you know, separate?
"We're going to go watch the film. Be really critical of ourselves. Ask what we can do better individually. Then move on and have a great week next week."
Hoyer's numbers were unimpressive in Saturday's loss, completing 8-for-11 for 89 yards with one interception and one fumble.
Shanahan had no complaints.
"There weren't any reads on his 11 attempts that I was upset with," Shanahan said, before turning his attention to the turnovers.
"Obviously, the ball slipped from him," he said. "That's unfortunate. It's not like you can tell him to grip it harder. It just slipped out of it and you have to deal with that.
"His pick (on a ball Goodwin had trouble securing) ... Marquise has to catch that ball. He threw it to him and I believe it was a third down, maybe it was a second down, but that keeps the drive alive. Just didn't catch it clean and the DB (Lewis-Harris) made a good play."
Hoyer had been penciled in to play about 20 snaps, which Shanahan figured would take no more than a quarter and a half.
But with three of the 49ers' first four possessions ending prematurely with turnovers, and with a fifth never even getting started because of a fumble on a Denver punt, backup C.J. Beathard didn't get into the game until there were just 42 seconds left in the half.
And even at that, Hoyer got just 24 scoreless snaps.
"You try to count everybody's reps and get them the amount of plays you wanted to keep them in for," Shanahan said. "We had those four turnovers in the first half. It was frustrating. We ended up not getting as many plays, which makes guys stay in longer."