There isn’t much difference and both are really correct. The problem with ‘any’ as raised here is the ambiguity. It could be taken to mean ‘any harm, if it occu

There isn’t much difference and both are really correct. The problem with ‘any’ as raised here is the ambiguity. It could be taken to mean ‘any harm, if it occurred’ or ‘any single bit of harm that did occur’. So in this sense ‘all harm’ would be safer and less ambiguous.