Mulvey, who guided the club to the A-League title last season, was informed of his dismissal late on Sunday afternoon, several hours after a report claiming he had been removed had been published by the Courier Mail.
Speaking at the unveiling of interim coach Frans Thijssen on Monday, Dobson acknowledge a major failing had occurred within the club's lines of communication.
"What happened yesterday in terms of process was not what we envisaged," he said.
"It was not something we wanted to do and it's not how we wanted to operate.
"Obviously we had a leak, we had a breach and we are investigating that breach. It is not something we take lightly. It's not something we accept as a club and it's not the way that we conduct ourselves."
According to Dobson, Mulvey has been removed in a bid to salvage the Roar's A-League and 2015 AFC Champions League hopes, the team having managed to record just one win in six games so far this term.
The managing director stopped short of confirming poor results had cost Mulvey his job, instead claiming the sacking was a result of 'deviation' from the club's football philosophy.
"This has been a tough process and not a decision that was reached lightly," he said.
"We are not giving up on this season and we are not giving up on the AFC Champions League campaign.
"Part of the reason this was done early in the season is to ensure we have a strong AFC Champions League campaign."
Veteran Dutch coach Thijssen became available to replace Mulvey after previously being courted for a backroom role alongside director of football Ken Stead.
"Frans was originally looked at for a Technical Director position at the club, which is why he's already in Brisbane," Dobson said.
"Frans is here to work with Ken Stead on bringing back our football philosophy.
"We are not looking at one man but a senior group, Frans with the support of Ken."
Speaking at the unveiling of interim coach Frans Thijssen on Monday, Dobson acknowledge a major failing had occurred within the club's lines of communication.
"What happened yesterday in terms of process was not what we envisaged," he said.
"It was not something we wanted to do and it's not how we wanted to operate.
"Obviously we had a leak, we had a breach and we are investigating that breach. It is not something we take lightly. It's not something we accept as a club and it's not the way that we conduct ourselves."
According to Dobson, Mulvey has been removed in a bid to salvage the Roar's A-League and 2015 AFC Champions League hopes, the team having managed to record just one win in six games so far this term.
The managing director stopped short of confirming poor results had cost Mulvey his job, instead claiming the sacking was a result of 'deviation' from the club's football philosophy.
"This has been a tough process and not a decision that was reached lightly," he said.
"We are not giving up on this season and we are not giving up on the AFC Champions League campaign.
"Part of the reason this was done early in the season is to ensure we have a strong AFC Champions League campaign."
Veteran Dutch coach Thijssen became available to replace Mulvey after previously being courted for a backroom role alongside director of football Ken Stead.
"Frans was originally looked at for a Technical Director position at the club, which is why he's already in Brisbane," Dobson said.
"Frans is here to work with Ken Stead on bringing back our football philosophy.
"We are not looking at one man but a senior group, Frans with the support of Ken."