It is understood the Brumbies were considering fighting the charge because Dagg was falling into the tackle. Peni will face a tribunal via video conference on Tuesday if the Brumbies appeal SANZAAR's initial decision.
The inconsistency and unpredictable nature of the SANZAAR citing process has been a source of frustration for Super Rugby teams and players for several years.
Brumbies fullback Tom Banks and Andy Muirhead have both been taken out in mid-air collisions and landed on their heads this season, but the offending players have not been suspended.
Otago Highlanders back-rower Elliot Dixon also escaped any sanction for a dangerous neck roll on star Brumbies flanker David Pocock three weeks ago.
However, Pretoria Bulls prop Pierre Schoeman was suspended for six weeks for biting Melbourne Rebels flanker Richard Hardwick.
But suspension was halved from 12 weeks to six after the panel took into consideration "mitigating factors including the players early guilty plea, his good character, his good disciplinary record and his remorse the judicial committee."
Peni was suspended for four games at the end of last year for a dangerous tackle in the National Rugby Championship when playing for the Western Force.
If he cops a significant ban, it would rule him out of the Brumbies' clash against the Melbourne Rebels next week and a two-game tour of South Africa.
The 24-year-old has been one of the Brumbies' best backs this season, scoring the equal-most tries (three) and beating the most defenders (21) en route to 438 run metres in seven games.
Brumbies coach Dan McKellar has several replacement options if Peni is unavailable, with Lausii Taliauli and James Dargaville pushing for recalls.
Another option could be sending Banks back to the wing and starting Muirhead at fullback for the Brumbies' next match against the Rebels at Canberra Stadium.
Any ban would be a blow in an already frustrating season for the Brumbies, who are 13th overall and fourth in the Australian conference with seven games remaining.
They're also sweating on the fitness of Isi Naisarani, who suffered an ankle injury against the Crusaders, while centre Andrew Smith pulled up with a sore shoulder.
Naisarani has been the Brumbies best player this season with the star No. 8 leading the team in tries, linebreaks and run metres.
McKellar hasn't had a round this season without at least one back-rower in the injury ward, but he'll welcome back superstar David Pocock for the Rebels clash.
Young gun Rob Valetini could also suit up against Melbourne and is expected to make his return from a knee injury in the John I Dent Cup for Wests this week.
Blindside flanker Lachy McCaffrey is nearing a return from a painful dislocated elbow injury he suffered against Queensland on April 7.
In a much-needed boost, Brumbies co-captain Christian Lealiifano will play against the Rebels after having three weeks off.
The inside centre played 16 games for Ulster in Europe before the Super Rugby season and was rested as part of a planned move by McKellar.
Eamonn Tiernan is a sports reporter with The Canberra Times
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