I suggest in the future showing some terminal float as suggested [REQUIRED] by NEC3.  In such case early activities would be tight as well as late activities. No warning shall be issued for consumption of available terminal float, it is yours!

If early critical activities are delayed by contractor then contractor terminal float is reduced because of contractor actions and no EOT is granted, if early critical activities are delayed by cause of client action terminal float is consumed and cannot be used to mitigate the effect of a compensation event.

Terminal float is a basic requirement to increase probabilities of success in project risk analysis. Not allowing for terminal float and require schedule not to show some early planned completion is self-defeating, is poor planning practice, to the point NEC3 requires all plans to show some terminal float. 

http://www.stevencevans.com/float/

Generally, there are 3 types of float:

• Project float (total float);
• Time-risk allowance (free float); and
• Period between planned completion and the completion date (terminal float).

As a general principle, NEC3 deals with each as follows:

• Total float – available either to the Employer or the Contractor (on a first come first served basis) to mitigate delays caused by compensation events or slow progress, i.e. its is ‘owned’ by the project;
• Free float – this is the duration allowed in each activity by the Contractor to account for the risk in not completing that activity in the minimum possible period. It is ‘owned’ by the Contractor and cannot be used to mitigate the effect of a compensation event;
• Terminal float – the duration between planned completion and the current contract Completion Date. This is also ‘owned’ by the Contractor and cannot be used to mitigate the effect of a compensation event.

It is important to remember that all the above must be shown on the Contractor’s programme and a failure to show it is a reason for the Project Manager to refuse to accept it.