This is another case of intention versus reception.
The builders probably thought they were having a bit of banter, and doing nothing wrong. The lady in question obviously did not share that perception.
It harks back to Dave Lee Travis's defence - 'I am a cuddly tactile person ...'.
That's fine, but it doesn't give you carte blanche to put your hands on any woman you take a fancy to, and expect her to enjoy it because you are the cuddly Hairy Cornflake.
Some people take behaviour like this in their stride, some are upset and intimidated - but the rule governing such behaviour should always be that the recipient governs the behaviour, how far it goes, and if it stops or continues.