An advertising agency was unfairly ruled out of contention for a £14 million contract with Tourism NI after a government website froze, the High Court has hread.
Counsel for AV Browne claimed it missed a tendering deadline due to the blockage in the system used for submitting bids.
Nicolas Hanna QC argued: "This amounted to a breach of the principles of equal treatment, non-discrimination and proportionality which apply to exercises of this kind."
Belfast firm AV Browne is taking legal action against the Northern Ireland Tourist Board in an attempt to be reinstated in the bidding process.
The contract, for advertising and design work over a period of up to four years, has yet to be awarded because of the court challenge.
The case centres on the operation of a procurement website run by the Department of Finance.
AV Browne, which has overseen a number of Tourism NI advertising campaigns in the past, completed the first phase of the tendering process.
But the court heard how problems arose when it tried to submit further information in time for the second stage.
Mr Hanna said that the web portal froze as an AV Browne employee attempted to send the details on an Apple computer just before the 3pm deadline on October 14 last year.
It meant she was unable to enter a figure into a box on the screen.
"As a result of that the tender submission was not completed, it had to be 100% complete and when she hit the submit button it failed to submit," the barrister explained.
"Shortly after 3pm whatever was causing this blockage freed up, but when she hit the button the tender was not accepted because it was late."
Mr Hanna claimed instructions on the tender website only dealt with Windows users on PCs.
"Apple computers were disadvantaged," he contended.
Mr Justice Deeny was also told how creative firms differ from other companies in the computer systems they favour.
In the business world generally around 85 percent use Windows, according to Mr Hanna.
But he added: "In the world of creatives, including advertising agencies, Apples are more popular - approximately 90 percent to 10 percent Windows."
The case continues.
