'heavy-fingered' originates from English, specifically a compound of 'heavy' + 'finger' with the adjectival suffix '-ed', formed to describe someone whose fingers are (figuratively or literally) heavy.

'heavy' comes from Old English 'hefig' meaning 'weighty' and 'finger' from Old English 'finger'; the adjectival form using '-ed' to indicate possessing that quality developed in modern English to create compounds such as 'heavy-fingered'.

Initially it would mean 'having physically heavy fingers'; over time it evolved to commonly mean 'clumsy or likely to press/handle things roughly or incorrectly', especially with keys or controls.