I was on the doorstep during that campaign, Foot was not a popular figure. Of course, that may have been because the constituency where I lived was definitely NOT a Labour heartland but there was enough self-inflicted damage to ridicule any suggestion that Foot was the victim of a 'dirty tricks' campaign.
There have been many debates since about the 'Falklands Factor' in that election but I'm not sure it was quite as big as later commentators make out. At the time the incompetent Labour/WetConservative governments of the '60s and '70s were still fresh in the memory. It wasn’t all sunlit uplands in 1982/3, but there were signs of improvement in many parts of the country. A Foot ministry would have taken us backwards and, whilst the alliance of Liberals/SDP/LabourDefectors was still a fractured coalition, it came very close to pushing Foot's Labour into third place in vote share.
Maybe the Thatcher government wouldn't have gained 58 seats without the Falklands, I can still see Labour losing 50 or more. Perhaps some of them would have been swept up by the Alliance and the final figures for the three main parties and combined 'others' have been 366/211/52/21 instead of 397/209/23/21. It's still a decisive win with an 82 majority, just not a landslide.