Hello, my name is XXXXX XXXXX it is my pleasure to assist you with your question today.
How long has he worked there for?
Hi, just finalising my advice, are you still online?
If he has been continuously employed at his place of work for less than 2 years then his employment rights will unfortunately be somewhat limited. Most importantly, he will not be protected against unfair dismissal. This means that his employer can dismiss him for more or less any reason, and without following a fair procedure, as long as their decision is not based on discriminatory grounds (i.e. because of gender, race, religion, age, a disability, sexual orientation, etc.) or because he was trying to assert any of his statutory rights (e.g. requesting paternity leave, etc.).
Unfortunately for him it means that the employer most certainly does not have to prove that he was guilty before dismissing - they can dismiss him for no reason at all or even based on a rumour.
If the dismissal had nothing to do with any of the above exceptions then he would not be able to challenge it and his only protection would be if he was not paid his contractual notice period, because unless he was dismissed for gross misconduct, he would be entitled to receive his contractual notice period. If he did not have a written contract in place he would be entitled to the minimum statutory notice period of 1 week. His employer would either have to allow him to work that notice period and pay him as normal, or they will have to pay him in lieu of notice.
If he was not paid his notice period when he was due one, that would amount to wrongful dismissal (which is different to unfair dismissal) and he could make a claim in an employment tribunal to recover the pay for the notice period that he should have been given. There is a 3-month time limit from the date of dismissal to submit the claim.