Two considerations:
First, Lazar should take his life in his and his only hands, since he's a professional player he should be able to take the best decisions for himself regardless of his family, if his family act like a dick.
What can a club that is paying you millions for playing football should expect from a man that cant even handle his family when the time of taking responsability will come?
Lauda told his dad, who didn't agree on him about his desire of a racing career, to fuck off and started racing with huge debts on his back despite coming from a rich family, all to do what he loved, Samardzic can do the same and prove everybody how much he really wants to join Inter as the next step forward in his career.
Second, Samardzic father is a real clown, this move can cost his son his entire reputation since he's still too young to have proven his real value, so playing this game really show how ignorant and entitled he is.
The risk is huge, since he's going back to Udinese and his club will not be happy of this shitshow, while other top clubs shall think very well before thinking about offering him a contract.
I bet the old man was one of those parents screaming insults from the stands at juvenile football games, brawling with other pissed off parents to "help" his son emerge, while have been a complete asshole his whole life and searching payback on his son's future.
In one word, disgusting.