This case appears prima facie illegal and unjustified if he is a 'workman' under the ID act.
For proven misconduct in the domestic enquiry held as per law, for a dismissal, no notice period is required except that all his legal dues ought to be paid within next working day.
Instead of terminating like you did, would it not be better to have obtained his resignation?
It is win win situation for both - you preempt legal exposure and employee leaves with no blot on his career.
24th July 2019 From India, Mumbai