Gomes allowed N'golo Kante's tame effort to squirm through his grasp early in the second half, before clumsily bringing down Jamie Vardy – who duly powered home his 12th goal of the season from the resulting penalty.
Watford, who had won their last two league fixtures prior to Saturday's defeat, did pull one back courtesy of Troy Deeney's penalty, but it was too little too late for Flores.
"It was a very close game, which we were expecting," he told Sky Sports.
"But their goals were accidents. They happen sometimes and they have happened today so we will move on.
"The dressing room is sad because we were so close to a result. The squad and supporters love Gomes, so we will support him and he will bounce back from this.
"He is very sad but we do not put this result down to him. We will remove that feeling because he is very important for us and has been at the beginning of the season.
"We have been good in the last few games but we were not at our best today, so now we must look forward."