How to reproduce:

we have a executable file on a read only mounted client:

[root@client mnt]# ls -l /mnt/
total 8
-rwxr-xr-x 1 root root 6439 Feb  1 14:51 test
[root@client mnt]# ./test
Hello World!

Then we try to write to the file, which will fail with EROFS:

[root@client mnt]# echo foo >> ./test
-bash: ./test: Read-only file system

Then run the file again:

[root@client mnt]# ./test
-bash: ./test: Text file busy

Note the executable fails to run across the whole cluster from this point, even on the clients without read only mount option.