Spurs went into the second leg against Dinamo Zagreb with a two-goal lead but Mislav Orsic produced a stunning hat trick as Dinamo won 3-2 on aggregate to dump the north London side out of the competition.
After the match, Hart posted the words "job done" with a tick on his Instagram account with the picture reading 3-0 to Dinamo.
The post was quickly deleted and the former England international issued an apology to the Spurs supporters and said it was a mistake from his social media team.
"Morning guys, I feel like I need to come on and make an apology on behalf of my social media team," Hart said in an Instagram video.
Joe Hart has released an apology video after his social media team posted 'job done' thinking Spurs had in fact won 3-0 last night 😳— ESPN UK (@ESPNUK) March 19, 2021
(via joehartofficial/Instagram) pic.twitter.com/pt3NmkuF0p
"It's just been brought to my attention, I've literally just woke up, but someone [on my social media team] thought we'd won 3-0 last night.
"As sloppy as it sounds it's the truth. They posted 'job done' -- that's unacceptable. I'm sure that's annoyed a lot of people and I'm sorry it's come to that.
"But it's obviously not come from me. I've got nothing but love for the club and support for the team. I'm just as down as the boys are.
"Apologies, unfortunately this happens but just know it didn't come from any other place other than a typo. Have a great day."