Shortly after his debut, Callihan became a member of "The Crew" faction, which also consisted of Jon Moxley, Dick Rick and Pepper Parks.

[6] Callihan began regularly competing for the Heartland Wrestling Association, and faced wrestlers including Chad Collyer and Nigel McGuinness.

[8] In 2008 at Uprising Callihan began feuding with IPW Junior Heavyweight Champion Billy Roc after a controversial double pin in a four-way match for the title, also involving Ricochet and Shiima Xion.

[9] The next month at Legally Insane Callihan and Roc teamed up in a losing effort against "The Messiahs of a New Age" of Dustin Rayz and Lou Roberts.

[12] On May 29, 2009, Callihan debuted for Pro Wrestling Syndicate at their Brawl For Paul event, where he lost a four-way match, also involving Xavier, Monsta Mack, and winner Trent Acid.

On November 11, 2008, Callihan made his Ring of Honor debut at Escalation in a losing effort in a four-corner survival match also involving Go Shiozaki, Rhett Titus, and Grizzly Redwood.

[13] Callihan appeared on the inaugural episode of Ring of Honor Wrestling on HDNet, which aired on March 21, losing to Kenny King.

was making his way to the ring, the Arena's video screens showed Callihan arguing with CZW management and demanding a title match.

[17] On October 25, 2009, Callihan defeated Danny Havoc to win the CZW Ultraviolent Underground Championship, but lost the title the same day to Thumbtack Jack.

On April 10, 2010, at Swingin For The Fences Callihan received a match for the CZW World Heavyweight Championship in a losing effort against Switchblade Conspiracy partner Jon Moxley.

Callihan won the title for a second time on July 14, 2012, in a 60-minute Ultraviolent Rules Iron Man match, but lost it the same day to AR Fox.

[22] Matches against wrestlers including Zack Sabre Jr., Brodie Lee, AR Fox, Bobby Fish, and Dave "Fit" Finlay at Evolve 9 followed.

[25][26] On June 5 at Enter The Dragon 2011, Callihan and Arik Cannon were joined by Pinkie Sanchez, and picked up a major win over the tag team of Open the Dream Gate Champion Masaaki Mochizuki and Susumu Yokosuka.

At a live event on December 6, 2013, Crowe assumed the character of a hacker, using a tablet computer to seize control of the arena lights, and attacked Kalisto.

[35] In August 2014, Johnston suffered a chipped tibia during a tag team match with Kalisto against The Ascension; the injury did not require surgery and he was able to return to the ring in November.

In September, he got his first series of wins at the 2012 Battle of Los Angeles; he defeated Willie Mack to advance to the quarterfinal round, where he beat T. J. Perkins.

At the 2013 Dynamite Duumvirate Tag Team Title Tournament, which took place on January 12, 2013, Callihan fought Younger in a non-tournament knockout or submission-only match.

He then started a losing streak being defeated by the likes of Jack Evans, Roderick Strong, Marty Scurll and Cody Rhodes at the first round of the Battle Of Los Angeles 2016.

On February 18, 2017, at Only Kings Understand Each Other, Callihan returned along with the debuting OI4K (Jake & Dave Crist), being defeated by The Superkliq (Adam Cole and The Young Bucks).

[52] On November 28, 2015, after being released from WWE, Johnston returned to the independent circuit, switching back to his Sami Callihan character where he appeared at All American Wrestling's Windy City Classic XI event.

[54] On December 4, 2015, he returned to Rockstar Pro Wrestling to face and defeat long time friend Jake Crist at the Killer XMas iPPV.

[55] On December 11, 2015, Callihan returned to Pro Wrestling Guerrilla in the first night of All-Star Weekend event, where he defeated Drew Gulak.

[56] Callihan debuted for PROGRESS Wrestling in May 2016 during the 2016 Super Strong Style 16 tournament, beating Matt Cross in the first round[57] and losing to Tommy End in the quarter finals.

[60] On November 2, 2019, Callihan debuted for Insane Championship Wrestling with a victory over BT Gunn at Fear & Loathing XII in Glasgow, Scotland.

He would return on Episode 9, now under the new name of Jeremiah Snake, as a member of the Reptile Tribe, teaming with Daga, Drago, and Kobra Moon in a losing effort against Aerostar and the Worldwide Underground (Johnny Mundo, PJ Black, and Taya).

[67] On November 5, 2017, at Bound for Glory, Callihan made his debut for Impact Wrestling as a villain by interfering in a 5150 Street Fight for the World Tag Team Championship, helping Ohio Versus Everything (Dave and Jake Crist) defeat Santana and Ortiz of The Latin American Xchange (LAX) to retain the title.

Callihan made his pay-per-view debut for Impact at the Redemption event on April 22, 2018, where oVe defeated Eddie Edwards, Moose and Tommy Dreamer in a House of Hardcore match.

Callihan would begin pursuing Swann's X Division Championship, unsuccessfully challenging him for the title on the March 22 episode of Impact and in an oVe Rules match at Rebellion.

Callihan began ascending up the ranks as he defeated Eddie Edwards in a Philly Street Fight at A Night You Can't Mist.

[88] Callihan along with Shane Page, Cannonball, and Dr. Cornwallis lost to Death Fighters (Raven, Akira, Jake Crist, and Jimmy Lloyd) at War Chamber.