Welcome to HealthcareMagic forum.
As per your description, it appears that he has sustained a traumatic injury
of the penile tissues / urethra
. Yes, this is a concerning problem and warrants immediate medical examination.
If he is able to sustain an erection without difficulty and if he is able to pass urine without difficulties, then it might not be a serious concern, nevertheless still concerning. So it is better that he see's a primary healthcare provider nearby.
Hope this answers your query.