The Titans had 14 players on the field in the 48th minute when prop David Shillington was allowed to go on the field to replace injured five-eighth Tyrone Roberts, who was on the ground on the opposite side to the interchange.

With the Raiders on the attack just 20m out from the Titans' line, Roberts took his place in the defensive line while Shillington was still on the field before the change was corrected.

Henry said there was some confusion when the interchange official accepted the card from Shillington while Roberts was still on the field.

"We just left the status quo and Shillo came off and Tyrone stayed on and he was replaced later on in the interchange anyway," Henry said.

"The match officials will have a look at it and we'll see what happens.

"When I saw Shillo go on and Tyrone and he went off the back [of the field], I reckon he was on there for about five seconds, so I think they recognised he wasn't off the other side.

"The interchange guy is supposed to sight it as far as I know and that didn't happen. We'll wait and see."

Raiders coach Ricky Stuart picked up the infringement as soon as it happened from his position on the sideline.

The oversight added to a dirty night for the Raiders, who were on the wrong side of a controversial try to Titans centre John Olive, which stole the game at the death.

The Raiders would have gone to the top of the table with their third victory from four games to go with last week's 24-all draw with the Newcastle Knights.

Now, after their first defeat, they face a tricky fortnight on the road, starting against the Canterbury Bulldogs at Belmore on Monday week.

It could be a different looking Raiders side that takes the field, with winger Edrick Lee and prop Jeff Lima sustaining suspected fractured thumbs. Both will have scans on Monday.

Former Melbourne Storm winger Sisa Waqa would be the likely replacement for Lee if the emerging Queensland Origin squad member is sidelined, while Luke Bateman, Rhys Kennedy and Mitch Barnett would be in line to take over Lima's spot on the bench.

"We've got a couple [of injuries], Edrick Lee and Jeff Lima are getting scans on two thumbs," Stuart said. "It doesn't look too flash for us."

Star halves Blake Austin and Aidan Sezer could return as early as the round-six game against the Parramatta Eels at Pirtek Stadium in a fortnight, while centre Joey Leilua will return from suspension for the game with the Bulldogs.

Shillington scored a try in his first game back in Canberra since leaving the Raiders after seven seasons with the club at the end of last year.