Exeter Chiefs boss Rob Baxter says some his side side's decision-making was 'scary' in their 40-35 loss at home to Bristol Bears at Sandy Park.
The Chiefs led 32-12 before Dan Frost was sin-binned in the 65th minute and Bristol scored three tries in four minutes to turn the game in its head.
The defeat means Exeter have suffered their worst-ever start to a Premiership season having lost all four of their opening matches.
It is 10 years since Baxter's side last lost four league games in succession as they prepare for a Friday night trip to bottom side Newcastle Falcons.
"It was a little bit scary watching us after we got that yellow card," Baxter told BBC Radio Devon.
"It's not just that we got the yellow card management side of things wrong by putting bodies into breakdowns which we didn't need, but actually we started missing tackles.
"You build your wall of 13 guys, you maybe keep one guy in the back field.
"It's really important as the first guy you stay alive to complete your tackle. No more than one other guy maybe competes in there and you have got yourself back on your feet again and you're ready to go again.
"We just couldn't do it, and it's a little bit scary.
"Some of the lads will be looking and I swear they'll be saying to me 'I don't really know what I did'.
"We had guys stepping off being our last defender and stepping in to go into breakdowns that were already won by Bristol and then they just walked down the outside to score tries.
"Some of it is a little bit silly almost, but we're not going to move unless we take responsibility for it."
Bristol's Gabriel Ibitoye scored three tries in less than 10 minutes at Sandy Park
Baxter, who helped guide Exeter to a Premiership and European Champions Cup double in 2020, says he will take responsibility for some aspects of the loss.
But he says his players must also bear the burden for their mistakes during the game which saw Exeter pick up a try-scoring bonus point after wingers Paul Brown-Bampoe and Immanual Feyi-Waboso each scored two tries.
"If we had no yellow card strategy in place I would have no problem putting my hand in the air and going 'it's our big problem, we haven't talked to the players about what we do with yellow cards, we actually stayed with our 15-man plan and it obviously backfired and didn't work'. That's my responsibility," he added.
"That isn't the case. This is where, if we want to become a good team and we want to compete right at the top end, we all have to take some responsibility for it.
"I'm certain they will, because we're very close to becoming a very good team.
"I think a good win today would have triggered us on probably a run of wins. Now we have to start again from scratch and that's the bit that's challenging."