Aside from the 1948 Aussies, there's been no test match 4th innings score of 350+ at Headingley, successful or otherwise. Bradman and Morris in that match, along with Mark Butcher and Moeen Ali are the only 4th innings centurions at Leeds
Something has to be behind the line - even if it's in the air when another part the foot is initially grounded. It was certainly close, but there's absolutely no reason for a spinner to be pushing the line that close. Umpire shouldn't have been given a decision to make.
Windies have thrown away a wonderful position - 50 runs conceded in a hapless 30 minutes after tea. Part-time spinner bowls a full-bunger first ball after the break, catch taken off a no-ball from a spinner, 4-balls all over the place