Swansea City manager Garry Monk praised his team after holding on for a 0-0 draw at Everton with 10 men.
Jonjo Shelvey was sent off 20 minutes from time for a second bookable offence, but the Swans held firm.
But Monk was unhappy that referee Kevin Friend failed to award a penalty when Antolin Alcaraz appeared to handle a Shelvey shot in the first half.
"I didn't know you were allowed to play with two goalkeepers, I thought it was only one," said Monk.
"And it's a great save from him - a great save - I'd be happy if my keeper pulled off that save.
"But somehow the ref didn't see it, everybody else saw it, it was clear for me and clear for everybody else on the pitch but we didn't get it so what can I say?"
His remarks came at the end of a week which saw Monk escape punishment for accusing Stoke City player Victor Moses of cheating and criticising referee Michael Oliver for awarding a spot kick in that 2-1 defeat on 19 October.
The Swans manager had a meeting with professional referees' boss Mike Riley on Friday, 31 October to discuss incidents in recent games.
Swansea's penalty appeal against Everton came in the 19th-minute of a match which saw the Swans cement their place in sixth spot in the Premier League - two points ahead of the Toffees.
Monk praised the effort and organisation of his team following the dismissal of Shelvey - with the Swansea boss having no complaints about that decision.
However, he is concerned about his players giving away "cheap" yellow cards and the fact Shelvey's dismissal was the fourth red card shown to one of his players this season.
"The cheap yellow that Jonjo gave away for the first was poor and you know it's going to leave us open to that situation.
"I took (striker Wilfried) Bony off for that reason thinking that one more slight challenge or his strength against the defender and it could have been a red.
"And if we could have got to the latter stages I probably would have changed Jonjo for the same reason, but unfortunately we couldn't reach that point and Jonjo was sent off before that.
"I'm extremely proud of them the way they dug in for a considerable period.
"I think for the effort the boys put in - especially in that last period - I said to them 'you'll probably never earn a harder point than you did there'.
"Coming to Everton - a very good place (and) a very hard place for us in the past it was a very well-earned point."
Swansea's next match in the Premier League is against Arsenal at home on Sunday, 9 November.