South Africa won impressively 27-9 to level the series and set up a decider in Cape Town next Saturday.
Gatland described the third Test as a “cup final” but the Lions head coach has much to do to wrest the initiative back from the Springboks.
The world champions showed a massive improvement in their performance from the first Test which the Lions won 22-17.
Saturday’s victory came two days after Erasmus, South Africa’s director of rugby, posted an hour-long video online in which he launched an unprecedented attack on Nic Berry, the first Test referee.
Gatland said he would hate to see rugby’s integrity compromised by such antics.
“I hope that doesn’t happen,” said the Lions coach. “We’ve got systems and processes in place and hopefully World Rugby will look at that in terms of making sure everyone follows the protocols. I think that’s important.
“I just hope it doesn’t get to a situation where we end up with things on Twitter and people airing their views that way rather than through the proper channels. I’ve found it quite strange that that approach was taken and it’s definitely not something I’ll get involved with.
“It’s important we keep the integrity of the game as much as we possibly can.”
Gatland was reluctant to comment on the performance of second Test referee Ben O’Keeffe but the coach did seem concerned about Cheslin Kolbe’s challenge in the air on Conor Murray which earned the South African wing a yellow card.
“It didn’t look great from where I was but he decided it was a yellow-card decision,” said Gatland.
The coach seemed at a loss to explain how the game slipped away from the Lions who had led 9-6 at the interval.
“We were happy with the way it was going at half-time but in the second half we just didn’t get anything, really. We just had no momentum, no opportunity to play and nothing at all from any kick-returns whether it was us or them, so that was disappointing,” said Gatland.
“We gave away some penalties. In fairness to them they scrummaged really well in the second half – drove a lot and got some reward from that.
“The players are obviously very disappointed but next Saturday is a cup final and that’s the way we’ve got to look at it and prepare for it.
“There’s a few things we’ve got to tidy up in terms of our game, but it’s one-all and they put a huge amount of emotion into that game so we’ve got that chance next week to hopefully tie the series up.”
Gatland was philosophical about the Lions being second best in the aerial battle.
“Sometimes these games go like that. We got nothing out of today but we did get a lot out of last week in terms of that aerial stuff. We knew it was coming and we worked on it through the week. But sometimes that just happens.”
Jacques Nienaber, the South Africa coach, refused to be drawn on the impact of the Erasmus video.
“Rassie, as director of rugby, had something on his mind, on his heart, that he wanted to get across,” Nienaber said on Sky Sports.
“For us, we discussed it, that is the message which went out from his side. From our side, we just stayed focused and did the rugby stuff on the field.”