Possible Clues:

• Tripped
• Tripped, faltered
• Missed a step and almost fell
• Missed a step and nearly fell
• 'Tripped, and one's belly was bleeding at last (8)'
• Took a trip?
• When one fell and lost one's head one's stomach was bleeding
• The South started to fall for a stomach that was bleeding
• When one lost one's head and fell, one's belly got 9 across
• And so it befell that this must have got bleeding